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1.
Respir Res ; 24(1): 280, 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37964270

RESUMEN

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic fatal disease with limited therapeutic options. The infiltration of monocytes and fibroblasts into the injured lungs is implicated in IPF. Enolase-1 (ENO1) is a cytosolic glycolytic enzyme which could translocate onto the cell surface and act as a plasminogen receptor to facilitate cell migration via plasmin activation. Our proprietary ENO1 antibody, HL217, was screened for its specific binding to ENO1 and significant inhibition of cell migration and plasmin activation (patent: US9382331B2). METHODS: In this study, effects of HL217 were evaluated in vivo and in vitro for treating lung fibrosis. RESULTS: Elevated ENO1 expression was found in fibrotic lungs in human and in bleomycin-treated mice. In the mouse model, HL217 reduced bleomycin-induced lung fibrosis, inflammation, body weight loss, lung weight gain, TGF-ß upregulation in bronchial alveolar lavage fluid (BALF), and collagen deposition in lung. Moreover, HL217 reduced the migration of peripheral blood mononuclear cells (PBMC) and the recruitment of myeloid cells into the lungs. In vitro, HL217 significantly reduced cell-associated plasmin activation and cytokines secretion from primary human PBMC and endothelial cells. In primary human lung fibroblasts, HL217 also reduced cell migration and collagen secretion. CONCLUSIONS: These findings suggest multi-faceted roles of cell surface ENO1 and a potential therapeutic approach for pulmonary fibrosis.


Asunto(s)
Fibrosis Pulmonar Idiopática , Neumonía , Ratones , Humanos , Animales , Leucocitos Mononucleares/metabolismo , Anticuerpos Monoclonales/uso terapéutico , Células Endoteliales/metabolismo , Fibrinolisina/metabolismo , Fibrinolisina/farmacología , Fibrinolisina/uso terapéutico , Pulmón/metabolismo , Fibrosis , Fibrosis Pulmonar Idiopática/inducido químicamente , Fibrosis Pulmonar Idiopática/tratamiento farmacológico , Fibrosis Pulmonar Idiopática/metabolismo , Neumonía/metabolismo , Colágeno/metabolismo , Bleomicina/toxicidad , Fibroblastos/metabolismo , Fosfopiruvato Hidratasa/metabolismo , Fosfopiruvato Hidratasa/farmacología , Fosfopiruvato Hidratasa/uso terapéutico , Ratones Endogámicos C57BL
2.
Environ Res ; 238(Pt 2): 117161, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37717800

RESUMEN

BACKGROUND: A growing number of studies have shown that prenatal exposure to chemical and non-chemical stressors has effects on fetal growth. The co-exposure of both better reflects real-life exposure patterns. However, no studies have included air pollutants and pregnancy-related anxiety (PrA) as mixtures in the analysis. METHOD: Using the birth cohort study method, 576 mother-child pairs were included in the Ma'anshan Maternal and Child Health Hospital. Evaluate the exposure levels of six air pollutants during pregnancy using inverse distance weighting (IDW) based on the pregnant woman's residential address and air pollution data from monitoring stations. Prenatal anxiety levels were assessed using the PrA Questionnaire. Generalized linear regression (GLR), quantile g-computation (QgC) and bayesian kernel machine regression (BKMR) were used to assess the independent or combined effects of air pollutants and PrA on birth weight for gestational age z-score (BWz). RESULT: The results of GLR indicate that the correlation between the six air pollutants and PrA with BWz varies depending on the different stages of pregnancy and pollutants. The QgC shows that during trimester 1, when air pollutants and PrA are considered as a whole exposure, an increase of one quartile is significantly negatively correlated with BWz. The BKMR similarly indicates that during trimester 1, the combined exposure of air pollutants and PrA is moderately correlated with a decrease in BWz. CONCLUSION: Using the method of analyzing mixed exposures, we found that during pregnancy, the combined exposure of air pollutants and PrA, particularly during trimester 1, is associated with BWz decrease. This supports the view that prenatal exposure to chemical and non-chemical stressors has an impact on fetal growth.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Efectos Tardíos de la Exposición Prenatal , Embarazo , Femenino , Humanos , Peso al Nacer , Estudios de Cohortes , Estudios Prospectivos , Teorema de Bayes , Exposición Materna , Contaminación del Aire/análisis , Contaminantes Atmosféricos/análisis , China , Ansiedad , Material Particulado/análisis
3.
Proc Natl Acad Sci U S A ; 117(42): 25991-25998, 2020 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-33020292

RESUMEN

Graphene has emerged as an attractive candidate for flexible transparent electrode (FTE) for a new generation of flexible optoelectronics. Despite tremendous potential and broad earlier interest, the promise of graphene FTE has been plagued by the intrinsic trade-off between electrical conductance and transparency with a figure of merit (σDC/σOp) considerably lower than that of the state-of-the-art ITO electrodes (σDC/σOp <123 for graphene vs. ∼240 for ITO). Here we report a synergistic electrical/optical modulation strategy to simultaneously boost the conductance and transparency. We show that a tetrakis(pentafluorophenyl)boric acid (HTB) coating can function as highly effective hole doping layer to increase the conductance of monolayer graphene by sevenfold and at the same time as an anti-reflective layer to boost the visible transmittance to 98.8%. Such simultaneous improvement in conductance and transparency breaks previous limit in graphene FTEs and yields an unprecedented figure of merit (σDC/σOp ∼323) that rivals the best commercial ITO electrode. Using the tailored monolayer graphene as the flexible anode, we further demonstrate high-performance green organic light-emitting diodes (OLEDs) with the maximum current, power and external quantum efficiencies (111.4 cd A-1, 124.9 lm W-1 and 29.7%) outperforming all comparable flexible OLEDs and surpassing that with standard rigid ITO by 43%. This study defines a straightforward pathway to tailor optoelectronic properties of monolayer graphene and to fully capture their potential as a generational FTE for flexible optoelectronics.

4.
Arch Gynecol Obstet ; 2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37773466

RESUMEN

BACKGROUND: It has been suggested that gestational diabetes mellitus (GDM) alters the growth trajectory of a fetus and increases the risk of abnormal birth weight. In spite of this, there is still a significant debate regarding the mode and optimal timing of diagnosing this condition. Our aim was to determine fetal growth velocity and birth biometry in pregnant women with GDM at varying risk levels. METHODS: We conducted a cohort study involving 1023 pregnant women at a maternity hospital in Ma'anshan, China. All women completed an oral glucose tolerance test at 24-28 weeks' gestation. We measured fetal head circumference (HC), femoral length (FL), abdominal circumference (AC), biparietal diameter (BPD), and estimate fetal weight (EFW) by ultrasound at 17, 24, 31, and 35 weeks' gestation, respectively. RESULTS: Overall, 5115 ultrasound scans were performed. Among both low-risk and medium-high-risk pregnant women at 17-24 weeks' gestation, GDM exposure was associated with an increase in fetal growth velocity. Neonates born to women with GDM at medium-high risk had significantly larger birth weights than those born to women without GDM, while this was not observed in women at low risk. CONCLUSION: In medium-high-risk pregnant women, exposure to GDM has a greater effect on the fetus, leading to abnormal fetal growth velocity that lasts beyond week 24. It is evident from our results that the effects of GDM on fetal growth differ between medium-high-risk pregnant women and low-risk pregnant women, and therefore a different screening program based on the risk factor for GDM is warranted.

5.
J Obstet Gynaecol Res ; 41(8): 1214-22, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25913643

RESUMEN

AIM: The aim of this study was to identify the incidence and risk factors of bacterial vaginosis among pregnant women. MATERIAL AND METHODS: Prospective data from a cohort of 668 pregnant women were used to identify potential risk factors for bacterial vaginosis during pregnancy by Cox proportional hazards regression. RESULTS: A total of 204 incident cases of bacterial vaginosis were diagnosed in 274.8 woman-years of follow-up. The bacterial vaginosis incidence rate was 0.74 per 1 woman-year and median prevalence during follow-up was 15.6%. In the adjusted model, changing underwear nearly everyday, miscarriage history, urinary tract infection during follow-up, husbands' education level, and concurrent trichomoniasis and candidiasis remained significantly associated with bacterial vaginosis (adjusted hazard ratio and 95% confidence interval were 1.87 [1.26-2.77]; 2.96 [1.96-4.47]; 2.41 [1.05-5.49]; 0.50 [0.32-0.77]; 1.82 [1.02-3.25]; 1.88 [1.30-2.70], respectively). CONCLUSION: Bacterial vaginosis during pregnancy can be affected by many factors, and some are indirectly acting factors. Further prospective studies that include a larger sample size and more information on the development of bacterial vaginosis are needed.


Asunto(s)
Complicaciones Infecciosas del Embarazo/epidemiología , Vaginosis Bacteriana/epidemiología , Adulto , China/epidemiología , Femenino , Humanos , Incidencia , Embarazo , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Vaginosis Bacteriana/etiología
6.
Plant Physiol Biochem ; 214: 108940, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39024781

RESUMEN

Plant growth is severely harmed by cadmium (Cd) contamination, while the addition of zinc (Zn) can reduce the toxic effects of Cd. However, the interaction between Cd and Zn on the molecular mechanism and cell wall of Cosmosbipinnatus is unclear. In this study, a transcriptome was constructed using RNA-sequencing. In C. bipinnatus root transcriptome data, the expression of 996, 2765, and 3023 unigenes were significantly affected by Cd, Zn, and Cd + Zn treatments, respectively, indicating different expression patterns of some metal transporters among the Cd, Zn, and Cd + Zn treatments. With the addition of Zn, the damage to the cell wall was reduced, both the proportion and content of polysaccharides in the cell wall were changed, and Cd accumulation was decreased by 32.34%. In addition, we found that Cd and Zn mainly accumulated in pectins, the content of which increased by 30.79% and 61.4% compared to the CK treatment. Thus, Zn could alleviate the toxicity of Cd to C. bipinnatus. This study revealed the interaction between Cd and Zn at the physiological and molecular levels, broadening our understanding of the mechanisms of tolerance to Cd and Zn stress in cosmos.


Asunto(s)
Cadmio , Pared Celular , Zinc , Cadmio/toxicidad , Zinc/metabolismo , Zinc/toxicidad , Zinc/farmacología , Pared Celular/metabolismo , Pared Celular/efectos de los fármacos , Transcriptoma/efectos de los fármacos , Perfilación de la Expresión Génica , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Raíces de Plantas/genética
7.
Oncol Rep ; 50(5)2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37800625

RESUMEN

The involvement of enolase­1 (ENO1), intracellularly or extracellularly, has been implicated in cancer development. Moreover, anticancer activities of an ENO1­targeting antibody has demonstrated the pathological roles of extracellular ENO1 (surface or secreted forms). However, although ENO1 was first identified as a glycolytic enzyme in the cytosol, to the best of our knowledge, extracellular ENO1 has not been implicated in glycolysis thus far. In the present study, the effects of extracellular ENO1 on glycolysis and other related pro­cancer activities were investigated in multiple myeloma (MM) cells in vitro and in vivo. Knockdown of ENO1 expression reduced lactate production, cell viability, cell migration and surface ENO1 expression in MM cells. Notably, addition of extracellular ENO1 protein in cancer cell culture enhanced glycolytic activity, hypoxia­inducible factor 1­α (HIF­1α) expression, glycolysis­related gene (GRG) expression and pro­cancer activities, such as cell migration, cell viability and tumor­promoting cytokine secretion. Consistently, these extracellular ENO1­induced cellular effects were inhibited by an ENO1­specific monoclonal antibody (mAb). In addition, extracellular ENO1­mediated glycolysis, GRG expression and pro­cancer activities were also reduced by HIF­1α silencing. Lastly, administration of an ENO1 mAb reduced tumor growth and serum lactate levels in an MM xenograft model. These results suggested that extracellular ENO1 (surface or secreted forms) enhanced a HIF­1α­mediated glycolytic pathway, in addition to its already identified roles. Therefore, the results of the present study highlighted the therapeutic potential of ENO1­specific antibodies in treating MM, possibly via glycolysis inhibition, and warrant further studies in other types of cancer.


Asunto(s)
Glucólisis , Mieloma Múltiple , Humanos , Anticuerpos Monoclonales/metabolismo , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Proliferación Celular/genética , Proteínas de Unión al ADN/metabolismo , Glucólisis/genética , Lactatos , Mieloma Múltiple/genética , Fosfopiruvato Hidratasa/genética , Fosfopiruvato Hidratasa/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Animales , Ratones , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Dis Markers ; 2022: 1720414, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36605375

RESUMEN

Objective: Our study assessed the predictive value of heart-type fatty acid-binding protein (H-FABP) for critically ill patients. Methods: 150 critically ill patients admitted to the emergency department of Beijing Chaoyang Hospital, Capital Medical University, were included in our study from August 2021 to April 2022. Serum H-FABP, procalcitonin (PCT), lactate (LAC), and other markers were determined within 1 h after admission. The Sequential Organ Failure Assessment (SOFA) score and the Acute Physiology and Chronic Health Evaluation II (APACHE II) were calculated. The independent predictors of 28-day mortality in critically ill patients were analyzed by logistic regression, and the receiver operating characteristic curve (ROC) was used to analyze the predictive value for 28-day mortality in critically ill patients. Results: Age, APACHE II, SOFA, GCS, LAC, H-FABP, IL-6, Scr, and D-dimer were significantly different in the nonsurvivor vs. survivor groups (P < 0.05), with H-FABP correlating with cTNI, Scr, PCT, and SOFA scores (P < 0.05). Logistic regression analysis showed that H-FABP, APACHE II, LAC, and age were independent predictors for 28-day mortality in critically ill patients (P < 0.05). The AUC of ROC curve in H-FABP was 0.709 (sensitivity 72.9%, specificity 66.1%, and cut-off 4.35), which was slightly lower than AUC of ROC curve in LAC (AUC 0.750, sensitivity 58.3%, specificity 76.1%, and cut-off 1.95) and APACHE II (AUC 0.731, sensitivity 77.1%, specificity 58.7%, and cut-off 12.5). However, statistically, there was no difference in the diagnostic value of H-FABP compared with the other two indicators (Z 1 = 0.669, P = 0.504; Z 2 = 0.383, P = 0.702). But H-FABP (72.9%) has higher sensitivity than LAC (58.3%). The combined evaluation of H-FABP+APACHE II score (AUC 0.801, sensitivity 71.7%, and specificity 78.2%; Z = 2.612, P = 0.009) had better diagnostic value than H-FABP alone and had high sensitivity (71.7%) and specificity (78.2%). Conclusion: H-FABP, LAC, APACHE II, and age can be used as independent risk factors affecting the prognosis of critically ill patients. Compared with using the above indicators alone, the H-FABP+APACHE II has a high diagnostic value, and the early and rapid evaluation is particularly important for the adjustment of treatment plans and prognosis.


Asunto(s)
Enfermedad Crítica , Proteína 3 de Unión a Ácidos Grasos , Humanos , Enfermedad Crítica/mortalidad , Proteína 3 de Unión a Ácidos Grasos/análisis , Ácido Láctico , Polipéptido alfa Relacionado con Calcitonina/metabolismo , Pronóstico , Estudios Retrospectivos , Curva ROC
9.
Mater Horiz ; 9(9): 2416-2424, 2022 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-35822671

RESUMEN

Defects, such as uncontrollable vacancies, will intensively degrade the material properties and device performance of CVD-grown transition metal dichalcogenides (TMDs). Although vacancies can be repaired by some post-processing measures, these treatments are usually time-consuming, complicated and may introduce uncontrollable chemical contaminants into TMDs. How to efficiently suppress the uncontrollable defects during CVD growth and acquire intrinsic high-quality CVD-grown TMDs without any after-treatment remains a critical challenge, and has not yet been well resolved. Here, an alternate-growth-etching (AGE) CVD method was demonstrated to fabricate defect-suppressed submillimeter-scale monolayer WS2 single crystals. Compared with normal CVD, the grain size of the as-grown WS2 can be enlarged by 4-5 times (∼520 µm) and the growth rate of ∼14.4 µm min-1 is also at a high level compared to reported results. Moreover, AGE-CVD can efficiently suppress atomic vacancies in WS2. In every growth-etching cycle, the etching of WS2 occurs preferentially at the defective sites, which will be healed at the following growth stage. As a result, WS2 monolayers obtained by AGE-CVD possess higher crystal quality, carrier mobility (8.3 cm2 V-1 s-1) and PL quantum yield (QY, 52.6%) than those by normal CVD. In particular, such a PL QY is the highest value ever reported for in situ CVD-grown TMDs without any after-treatment, and is even comparable to the values of mechanically exfoliated samples. This AGE-CVD method is also appropriate for the synthesis of other high-quality TMD single crystals on a large-scale.

10.
Mol Cancer Ther ; 21(8): 1337-1347, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35700013

RESUMEN

Prostate cancer is one of the most common causes of cancer death in men worldwide, and the treatment options are limited for patients with advanced stages of prostate cancer. Upon oncogenic or inflammatory stimulation, tumor cells or immune cells express cell surface enolase-1 (ENO1) as plasminogen receptor to facilitate their migration via plasmin activation. Little is known about the roles of ENO1 in prostate cancer, especially in the tumor microenvironment (TME). We hypothesized that targeting surface ENO1 with specific mAbs would exert multifactorial therapeutic potentials against prostate cancer. In vivo, we showed ENO1 mAb (HuL227) reduced the growth of subcutaneous PC-3 xenograft, monocytes recruitment, and intratumoral angiogenesis. In a PC-3 intratibial implantation model, HuL227 reduced tumor growth and osteoclast activation in the bone. To investigate the antitumor mechanism of ENO1 mAb, we found that blocking surface ENO1 significantly reduced VEGF-A-induced tube formation of endothelial cells in vitro. Furthermore, HuL227 inhibited inflammation-enhanced osteoclasts activity and the secretion of invasion-related cytokines CCL2 and TGFß from osteoclasts. In addition, inflammation-induced migration and chemotaxis of androgen-independent prostate cancer cells were dose-dependently inhibited by HuL227. In summary, we showed that, ENO1 mAb targets multiple TME niches involved in prostate cancer progression and bone metastasis via a plasmin-related mechanism, which may provide a novel immunotherapy approach for men with advanced prostate cancer.


Asunto(s)
Neoplasias de la Próstata , Microambiente Tumoral , Animales , Línea Celular Tumoral , Células Endoteliales/metabolismo , Fibrinolisina , Humanos , Inflamación , Masculino , Células PC-3 , Fosfopiruvato Hidratasa/metabolismo , Neoplasias de la Próstata/patología
11.
Nanoscale Horiz ; 7(7): 743-751, 2022 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-35482297

RESUMEN

The synthesis of large-scale monolayer single-crystal MX2 (M = Mo, W; X = S, Se), a typical transition metal dichalcogenide (TMD), is the premise for their future applications. Compared with insulating substrates such as SiO2 and sapphire, Au is more favourable for the fast growth of TMDs by chemical vapor deposition (CVD). Recently, large-scale single-crystal WX2 was successfully grown and transferred on Au. In sharp contrast, the growth and transfer for monolayer MoX2 is still very challenging, because Au has a higher solubility of Mo and stronger interaction with MoX2 than WX2. Compared with the most studied MoS2, MoSe2 is superior in many aspects because of the narrower band gap and tunable excitonic charging effects. However, the synthesis of large-scale single-crystal MoSe2 on Au has not been reported so far. Here, a pre-alloying CVD method was developed to solve the problems for the growth and non-destructive transfer of MoX2. It has realized the ultrafast growth (30 s) of submillimeter-scale (560 µm) single-crystal MoSe2 for the first time. As-grown samples are strictly monolayers with good optical and electrical properties, which can be easily transferred without sacrificing Au foils by the electrochemical bubbling method. It was found that pre-alloying not only passivates the energetically active sites on Au but also weakens the interaction between Au and MoSe2, which is responsible for the ultrafast growth and easy transfer of MoSe2. This method is also universal for the fast growth and non-destructive transfer of other 2D TMDs.

12.
Nat Commun ; 12(1): 1798, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33741964

RESUMEN

The challenges of developing neuromorphic vision systems inspired by the human eye come not only from how to recreate the flexibility, sophistication, and adaptability of animal systems, but also how to do so with computational efficiency and elegance. Similar to biological systems, these neuromorphic circuits integrate functions of image sensing, memory and processing into the device, and process continuous analog brightness signal in real-time. High-integration, flexibility and ultra-sensitivity are essential for practical artificial vision systems that attempt to emulate biological processing. Here, we present a flexible optoelectronic sensor array of 1024 pixels using a combination of carbon nanotubes and perovskite quantum dots as active materials for an efficient neuromorphic vision system. The device has an extraordinary sensitivity to light with a responsivity of 5.1 × 107 A/W and a specific detectivity of 2 × 1016 Jones, and demonstrates neuromorphic reinforcement learning by training the sensor array with a weak light pulse of 1 µW/cm2.

13.
Science ; 369(6504): 670-674, 2020 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-32764066

RESUMEN

Identifying two-dimensional layered materials in the monolayer limit has led to discoveries of numerous new phenomena and unusual properties. We introduced elemental silicon during chemical vapor deposition growth of nonlayered molybdenum nitride to passivate its surface, which enabled the growth of centimeter-scale monolayer films of MoSi2N4 This monolayer was built up by septuple atomic layers of N-Si-N-Mo-N-Si-N, which can be viewed as a MoN2 layer sandwiched between two Si-N bilayers. This material exhibited semiconducting behavior (bandgap ~1.94 electron volts), high strength (~66 gigapascals), and excellent ambient stability. Density functional theory calculations predict a large family of such monolayer structured two-dimensional layered materials, including semiconductors, metals, and magnetic half-metals.

14.
Nat Commun ; 11(1): 1205, 2020 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-32139679

RESUMEN

Since its invention in the 1960s, one of the most significant evolutions of metal-oxide-semiconductor field effect transistors (MOS-FETs) would be the three dimensionalized version that makes the semiconducting channel vertically wrapped by conformal gate electrodes, also recognized as FinFET. During the past decades, the width of fin (W[Formula: see text]) in FinFETs has shrunk from about 150 nm to a few nanometers. However, W[Formula: see text] seems to have been levelling off in recent years, owing to the limitation of lithography precision. Here, we show that by adapting a template-growth method, different types of mono-layered two-dimensional crystals are isolated in a vertical manner. Based on this, FinFETs with one atomic layer fin are obtained, with on/off ratios reaching [Formula: see text]. Our findings push the FinFET to the sub 1 nm fin-width limit, and may shed light on the next generation nanoelectronics for higher integration and lower power consumption.

15.
Adv Mater ; 32(9): e1907288, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31977113

RESUMEN

In a modern electronics system, charge-coupled devices and data storage devices are the two most indispensable components. Although there has been rapid and independent progress in their development during the last three decades, a cofunctionality of both sensing and memory at single-unit level is yet premature for flexible electronics. For wearable electronics that work in ultralow power conditions and involve strains, conventional sensing-and-memory systems suffer from low sensitivity and are not able to directly transform sensed information into sufficient memory. Here, a new transformative device is demonstrated, which is called "sen-memory", that exhibits the dual functionality of sensing and memory in a monolithic integrated circuit. The active channel of the device is formed by a carbon nanotube thin film and the floating gate is formed by a controllably oxidized aluminum nanoparticle array for electrical- and optical-programming. The device exhibits a high on-off current ratio of ≈106 , a long-term retention of ≈108 s, and durable flexibility at a bending strain of 0.4%. It is shown that the device senses a photogenerated pattern in seconds at zero bias and memorizes an image for a couple of years.

16.
ACS Appl Mater Interfaces ; 11(19): 17629-17636, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-31026138

RESUMEN

It is essentially important to synthesize uniform graphene films with a controlled number of layers because their properties strongly depend on the number of layers. Although chemical vapor deposition (CVD) on Cu has been widely used to synthesize large-area graphene films, the growth on solid and liquid Cu (L-Cu) suffers from poor thickness uniformity with a great number of adlayers and difficulty in forming continuous films even after a long growth time of hours, respectively. Here, we found that nonuniform graphene films initially grown on solid Cu (S-Cu) foil can rapidly transform into continuously uniform monolayer graphene film on L-Cu within 3 min. Moreover, the films obtained show larger grain size, higher quality, better optical and electrical properties, and better performance in organic light-emitting diode applications than the original films grown on S-Cu foil. By using carbon isotope labeling, we revealed that the multilayer-to-monolayer transition of graphene on L-Cu experiences etching-"self-aligning"-coalescence processes. This two-step CVD method not only opens up a new way for the rapid growth of uniform monolayer graphene films but also provides helpful information for the controlled growth of uniform monolayers of other 2D materials such as monolayer h-BN.

17.
Nat Commun ; 10(1): 2809, 2019 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-31243279

RESUMEN

Large-area high-quality AB-stacked bilayer graphene films are highly desired for the applications in electronics, photonics and spintronics. However, the existing growth methods can only produce discontinuous bilayer graphene with variable stacking orders because of the non-uniform surface and strong potential field of the solid substrates used. Here we report the growth of wafer-scale continuous uniform AB-stacked bilayer graphene films on a liquid Pt3Si/solid Pt substrate by chemical vapor deposition. The films show quality, mechanical and electrical properties comparable to the mechanically exfoliated samples. Growth mechanism studies show that the second layer is grown underneath the first layer by precipitation of carbon atoms from the solid Pt, and the small energy requirements for the movements of graphene nucleus on the liquid Pt3Si enables the interlayer epitaxy to form energy-favorable AB stacking. This interlayer epitaxy also allows the growth of ABA-stacked trilayer graphene and is applicable to other liquid/solid substrates.

18.
ACS Appl Mater Interfaces ; 11(12): 11699-11705, 2019 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-30839190

RESUMEN

Carbon nanotube (CNT) thin-film transistors are expected to be promising for use in flexible electronics including flexible and transparent integrated circuits and in wearable chemical and physical sensors and for driving the circuits of flexible display panels. However, current devices based on CNT channels suffer from poor performance uniformity and low manufacturing yield; therefore, they are still far from being practical. This is usually caused by nonuniform deposition of the semiconducting CNTs and the rough surface of flexible substrates. Here, we report CNT thin-film transistors (TFTs) driving a flexible 64 × 64 pixel active matrix light-emitting diode display (AMOLED) by improving the formation of uniform CNT films and developing a new pretreatment technique for flexible substrates. The achieved AMOLED has uniform brightness and a high yield of 99.93% in its 4096 pixels. More than 8000 TFTs with high-purity semiconducting CNTs as the channel material show an average on-off current ratio of ∼107 and a carrier mobility of 16 cm2 V-1 s-1. The standard deviations of the on-state current and the carrier mobility are 4.1 and 6.5%, respectively. Our result shows that the panel driven by high-purity semiconducting CNTs is a promising strategy for the development of next-generation flexible, large-area displays.

19.
Nat Commun ; 10(1): 2302, 2019 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-31127105

RESUMEN

Anisotropy in crystals arises from different lattice periodicity along different crystallographic directions, and is usually more pronounced in two dimensional (2D) materials. Indeed, in the emerging 2D materials, electrical anisotropy has been one of the recent research focuses. However, key understandings of the in-plane anisotropic resistance in low-symmetry 2D materials, as well as demonstrations of model devices taking advantage of it, have proven difficult. Here, we show that, in few-layered semiconducting GaTe, electrical conductivity anisotropy between x and y directions of the 2D crystal can be gate tuned from several fold to over 103. This effect is further demonstrated to yield an anisotropic non-volatile memory behavior in ultra-thin GaTe, when equipped with an architecture of van der Waals floating gate. Our findings of gate-tunable giant anisotropic resistance effect pave the way for potential applications in nanoelectronics such as multifunctional directional memories in the 2D limit.

20.
Sci Adv ; 4(5): eaap9264, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29736413

RESUMEN

Single-wall carbon nanotubes (SWCNTs) are ideal for fabricating transparent conductive films because of their small diameter, good optical and electrical properties, and excellent flexibility. However, a high intertube Schottky junction resistance, together with the existence of aggregated bundles of SWCNTs, leads to a degraded optoelectronic performance of the films. We report a network of isolated SWCNTs prepared by an injection floating catalyst chemical vapor deposition method, in which crossed SWCNTs are welded together by graphitic carbon. Pristine SWCNT films show a record low sheet resistance of 41 ohm □-1 at 90% transmittance for 550-nm light. After HNO3 treatment, the sheet resistance further decreases to 25 ohm □-1. Organic light-emitting diodes using this SWCNT film as anodes demonstrate a low turn-on voltage of 2.5 V, a high current efficiency of 75 cd A-1, and excellent flexibility. Investigation of isolated SWCNT-based field-effect transistors shows that the carbon-welded joints convert the Schottky contacts between metallic and semiconducting SWCNTs into near-ohmic ones, which significantly improves the conductivity of the transparent SWCNT network. Our work provides a new avenue of assembling individual SWCNTs into macroscopic thin films, which demonstrate great potential for use as transparent electrodes in various flexible electronics.

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