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2.
Chem Rev ; 124(1): 164-209, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38044580

RESUMO

The performance of a chemical reaction is critically dependent on the electronic and/or geometric structures of a material in heterogeneous catalysis. Over the past century, the Sabatier principle has already provided a conceptual framework for optimal catalyst design by adjusting the electronic structure of the catalytic material via a change in composition. Beyond composition, it is essential to recognize that the geometric atomic structures of a catalyst, encompassing terraces, edges, steps, kinks, and corners, have a substantial impact on the activity and selectivity of a chemical reaction. Crystal-phase engineering has the capacity to bring about substantial alterations in the electronic and geometric configurations of a catalyst, enabling control over coordination numbers, morphological features, and the arrangement of surface atoms. Modulating the crystallographic phase is therefore an important strategy for improving the stability, activity, and selectivity of catalytic materials. Nonetheless, a complete understanding of how the performance depends on the crystal phase of a catalyst remains elusive, primarily due to the absence of a molecular-level view of active sites across various crystal phases. In this review, we primarily focus on assessing the dependence of catalytic performance on crystal phases to elucidate the challenges and complexities inherent in heterogeneous catalysis, ultimately aiming for improved catalyst design.

3.
Int Heart J ; 64(6): 970-978, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37967976

RESUMO

Hypertensive patients with snoring and elevated plasma homocysteine levels are common. When these factors are combined, the risk of coronary heart disease (CHD) is high. Herein, we developed and validated an easy-to-use nomogram to predict high-risk CHD in snoring hypertensive patients with elevated plasma homocysteine.Snoring patients (n = 1,962) with hyperhomocysteinemia and hypertension were divided into training (n = 1,373, 70%) and validation (n = 589, 30%) sets. We extracted CHD predictors using multivariate Cox regression analysis, then constructed a nomogram model. Internal validation using 1,000 bootstrap resampling was performed to assess the consistency and discrimination of the predictive model using the area under the receiver operating characteristic curve (AUC) and calibration plots.We constructed a nomogram model with the extracted predictors, including age, waist-height ratio, smoking, and low-density lipoprotein cholesterol levels. The AUCs of the training and validation cohorts at 80 months were 0.735 (95% CI: 0.678-0.792) and 0.646 (95% CI: 0.547-0.746), respectively. The consistency between the observed CHD survival and the probability of CHD survival in the training and validation sets was acceptable based on the calibration plots. A total of more than 151 points in the nomogram can be used in the identification of high-risk patients for CHD among snoring hypertensive patients with elevated plasma homocysteine.We developed a CHD risk prediction model for snoring hypertension patients with hyperhomocysteinemia. Our findings provide a useful clinical tool for the rapid identification of high-risk CHD at an early stage.


Assuntos
Doença das Coronárias , Hiper-Homocisteinemia , Hipertensão , Humanos , Hiper-Homocisteinemia/complicações , Hiper-Homocisteinemia/diagnóstico , Hiper-Homocisteinemia/epidemiologia , Ronco/epidemiologia , Doença das Coronárias/complicações , Doença das Coronárias/diagnóstico , Doença das Coronárias/epidemiologia , Hipertensão/complicações , Hipertensão/epidemiologia , Homocisteína , Nomogramas
4.
Plant Physiol Biochem ; 204: 108068, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37852067

RESUMO

Flavonoids, such as anthocyanins and proanthocyanidins (PAs), play essential roles in plant growth, development, and stress response. Red-fleshed apples represent a valuable germplasm resource with high flavonoid content. Understanding and enriching the regulatory network controlling flavonoid synthesis in red-fleshed apples holds significant importance for cultivating high-quality fruits. In this study, we successfully isolated an NAC transcription factor, MdNAC14-Like, which exhibited a significant negative correlation with the content of anthocyanin. Transient injection of apple fruit and stable expression of callus confirmed that MdNAC14-Like acts as an inhibitor of anthocyanin synthesis. Through yeast monohybrid, electrophoretic mobility shift, and luciferase reporter assays, we demonstrated the ability of MdNAC14-Like to bind to the promoters of MdMYB9, MdMYB10, and MdUFGT, thus inhibiting their transcriptional activity and subsequently suppressing anthocyanin synthesis. Furthermore, our investigation revealed that MdNAC14-Like interacts with MdMYB12, enhancing the transcriptional activation of MdMYB12 on the downstream structural gene MdLAR, thereby promoting PA synthesis. This comprehensive functional characterization of MdNAC14-Like provides valuable insights into the intricate regulatory network governing anthocyanin and PA synthesis in apple.


Assuntos
Malus , Proantocianidinas , Malus/genética , Malus/metabolismo , Antocianinas/metabolismo , Proantocianidinas/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Flavonoides/metabolismo
6.
Injury ; 54(10): 110977, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37684116

RESUMO

OBJECTIVE: To investigate the clinical efficacy of three-dimensional (3D) printing-assisted shaping titanium cage combined with Masquelet technology in the treatment of calcaneal infectious defects. METHODS: A retrospective analysis was performed of the data from nine patients with chronic calcaneal infection defects treated with distal gastronal flap coverage and one patient with free anterolateral thigh flap coverage, also using a 3D printing-assisted shaping titanium cage combined with both mask technology and rib autografting from January 2017 to January 2019. There were seven males and three females, with a mean age of 37 years (range, 17-52 years). The injury mechanism of the 10 patients included four motor vehicle incidents, four high fall injuries, and two rolling compactions. All patients were treated by two⁃stage procedures. The first stage included debridement, polymethyl methacrylate (PMMA) filling, and regional flap coverage. The soft tissue defect of the 10 cases included 80 cm2 in four cases and 56 cm2, 40 cm2, and 15 cm2 in each of two cases. The bone defect was 24 cm3 and 18 cm3 in each of four cases and 3 cm3 in two cases. The second stage was the mask technology of 3D printing-assisted shaping titanium cage combined with rib autografting. Time of bone union, calcaneus morphology, implant position, and the Maryland and AOFAS hind foot scores were recorded to evaluate the clinical outcome. RESULTS: All 10 patients were followed up for a mean of 18.5 months (range, 12-30 months). Infection occurred in two patients 2 months after the first stage operation and were successfully treated by debridement and PMMA replacement. The incision of the other eight cases all healed successfully. Cultures from the 10 cases included five cases of methicillin-resistant Staphylococcus aureus, three cases of S. aureus, and one case each of Escherichia coli and Pseudomonas aeruginosa. All 10 patients exhibited calcaneus bone union after the second stage operation. The mean time for bone union was 4.32 (range, 3-8) months. Bone trabeculae were observed in a CT scan 13 (range, 10-22) months post-operation. The mean Maryland score at 12 months post-operation was 92 (range, 86-98) and the mean AOFAS ankle hind foot score was 89.8 (range, 83-100). CONCLUSION: Three-dimensional printing-assisted shaping titanium cages and Masquelet technology may be effective methods for the treatment of infectious calcaneal defects.


Assuntos
Calcâneo , Staphylococcus aureus Resistente à Meticilina , Osteomielite , Feminino , Masculino , Humanos , Adulto , Titânio , Polimetil Metacrilato , Estudos Retrospectivos , Staphylococcus aureus , Osteomielite/diagnóstico por imagem , Osteomielite/cirurgia , Impressão Tridimensional , Calcâneo/diagnóstico por imagem , Calcâneo/cirurgia
8.
Zhongguo Gu Shang ; 36(8): 708-13, 2023 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-37605907

RESUMO

OBJECTIVE: To explore asurgical methods for replantation of severed finger. METHODS: From January 2018 to November 2022, 8 amputated-finger patients were performed surgical reconstructions by using polyfoliate free flaps with the first dorsal metatarsal artery, including 7 males and 1 female, aged from 20 to 55 years old, and defect areas ranged from (1.0 to 2.0) cm×(3.0 to 4.5) cm. Finger pulp sensation, shape and other relevant parameters were assessed following the upper extremity functional evaluation standard, which was put forward by Hand Surgery Branch of Chinese Medical Association. And maryland foot functional score was used to evaluate foot function. RESULTS: Amputated fingers and flaps of all the 8 patients were survived. All patients were followed up for 4 to 20 months, their finger color and temperature tured to normal, with good wear-resistance and cold-resistance. According to Hand Surgery Branch of Chinese Medical Association, functional score ranged 61 to 92;4 patients got excellent result and 4 good. Maryland foot functional score ranged from 93 to 100;and 8 patients got excellent result. CONCLUSION: It is feasible to repair severed fingers with soft tissue defects using polyfoliate free flaps that driven by the flippers of the first and second toes of the foot. This method ccould bridge blood vessels, increase soft tissue volume of the injured finger, and avoid finger shortening, with high patient satisfaction.


Assuntos
, Procedimentos de Cirurgia Plástica , Masculino , Humanos , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Pé/cirurgia , Extremidade Inferior , Retalhos Cirúrgicos , Dedos do Pé
9.
Front Genet ; 14: 1132242, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36845384

RESUMO

The study of tumor microenvironment plays an important role in the treatment of cancer patients. In this paper, intelligent medical Internet of Things technology was used to analyze cancer tumor microenvironment-related genes. Through experiments designed and analyzed cancer-related genes, this study concluded that in cervical cancer, patients with high expression of P16 gene had a shorter life cycle and a survival rate of 35%. In addition, through investigation and interview, it was found that patients with positive expression of P16 and Twist genes had a higher recurrence rate than patients with negative expression of both genes; high expression of FDFT1, AKR1C1, and ALOX12 in colon cancer is associated with short survival; high expressions of HMGCR and CARS1 is associated with longer survival; overexpression of NDUFA12, FD6, VEZT, GDF3, PDE5A, GALNTL6, OPMR1, and AOAH in thyroid cancer is associated with shortened survival; high expressions of NR2C1, FN1, IPCEF1, and ELMO1 is associated with prolonged survival. Among the genes associated with the prognosis of liver cancer, the genes associated with shorter survival period are AGO2, DCPS, IFIT5, LARP1, NCBP2, NUDT10, and NUDT16; the genes associated with longevity are EIF4E3, EIF4G3, METTL1, NCBP1, NSUN2, NUDT11, NUDT4, and WDR4. Depending on the prognostic role of genes in different cancers, they can influence patients to achieve the effect of reducing patients' symptoms. In the process of disease analysis of cancer patients, this paper uses bioinformation technology and Internet of things technology to promote the development of medical intelligence.

10.
Small ; 19(20): e2207311, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36782084

RESUMO

The threshold voltage (Vth ) adjustment of complementary metal-oxide-semiconductor (CMOS) thin film transistors (TFTs) is one of the research hotspots due to its key role in energy consumption control of CMOS circuits. Here, ultralow-power flexible CMOS circuits based on well-matched enhancement-mode (E-mode) CMOS single-walled carbon nanotube (SWCNT) TFTs are successfully achieved through tuning the work function of gate electrodes, electron doping, and printing techniques. E-mode P-type CMOS SWCNT TFTs with the full-solution procedure are first obtained through decreasing the work function of Ag gate electrodes directly caused by the deposition of bismuth iodide (BiI3 )-doped solid-state electrolyte dielectrics. After synthetic optimization of dielectric compositions and semiconductor printing process, the flexible printed E-mode SWCNT TFTs show the high Ion /Ioff ratios of ≈106 , small subthreshold swing (SS) of 70-85 mV dec-1 , low operating voltages of ≈0.5 to -1.5 V, good stability and excellent mechanical flexibility during 10 000 bending cycles. E-mode N-type SWCNT TFTs are then selectively achieved via printing the polarity conversion ink (2-Amino-2-methyl-1-propanol (AMP)  as electron  doping agent) in P- type TFT channels. Last, printed SWCNT CMOS inverters are successfully constructed with full rail-to-rail output characteristics and the record unit static power consumption of 6.75 fW µm-1 at VDD of 0.2 V.

11.
Nanoscale ; 15(11): 5317-5326, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36811360

RESUMO

A universal roll-to-roll (R2R) printing approach was developed to construct large area (8 cm × 14 cm) semiconducting single-walled carbon nanotube (sc-SWCNT) thin films on flexible substrates (such as polyethylene terephthalate (PET), paper, and Al foils) at a printing speed of 8 m min-1 using highly concentrated sc-SWCNT inks and crosslinked poly-4-vinylphenol (c-PVP) as the adhesion layer. Bottom-gated and top-gated flexible printed p-type TFTs based on R2R printed sc-SWCNT thin films exhibited good electrical properties with a carrier mobility of ∼11.9 cm2 V-1 s-1, Ion/Ioff ratios of ∼106, small hysteresis, and a subthreshold swing (SS) of 70-80 mV dec-1 at low gate operating voltages (±1 V), and excellent mechanical flexibility. Furthermore, the flexible printed complementary metal oxide semiconductor (CMOS) inverters demonstrated rail-to-rail voltage output characteristics under an operating voltage as low as VDD = -0.2 V, a voltage gain of 10.8 at VDD = -0.8 V, and power consumption as low as 0.056 nW at VDD = -0.2 V. To the best of our knowledge, the electrical properties of the printed SWCNT TFTs (such as Ion/Ioff ratio, mobility, operating voltage, and mechanical flexibility) and printed CMOS inverters based on the R2R printed sc-SWCNT active layer in this work are excellent compared to those of R2R printed SWCNT TFTs reported in the literature. Consequently, the universal R2R printing method reported in this work could promote the development of fully printed low-cost, large-area, high-output, and flexible carbon-based electronics.

12.
Soft Robot ; 10(2): 280-291, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35944266

RESUMO

In this article, a cable-driven elastic backbone worm-like robot (named "SpringWorm") of decimeter-level size is designed, which has high adaptability in crack inspection of the weld between reactor pressure vessel (RPV) and control rod drive mechanisms. The robot consists of a body that adopts a rectangular helix spring backbone driven by four cables and the flexible claws embedded with distributed electromagnets. Combining the omnidirectional deformation of the backbone and the passive deformation adsorption of the claws, the robot can achieve a variety of gaits. Based on the approaches of geometric analysis and transformation matrices of the coordinate frame, a kinematic model of the cable-driven backbone has been established. Moreover, a mechanical model considering the friction between the cable and the backbone has also been established. The top position and the bending angle of the backbone obtained by the theory, simulation, and experiment are in good agreement. In addition, the errors of the driving force between simulation and experimental results are also small. SpringWorm is 670 g, measures 206 × 65 × 75 mm, has a maximum speed of 8.9 mm/s, and has a maximum payload of 1 kg. The robot can climb over 2-cm-tall steps and 4-cm-deep ditches, and climb and turn on the vertical wall, on the pipe with a radius of 31 cm, and on the spherical surface of RPV.

13.
Adv Mater ; 34(40): e2204066, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36030367

RESUMO

The development of eco-friendly, ultralow-power and easy-to-process electronics is facing dominant challenges in emerging off-the-grid applications, such as the Internet of Things (IoTs) and extreme environment explorations at the south/north pole, in the deep sea, and in outer space. Eco-friendly, biodegradable, lightweight, and flexible paper-based electronics can provide many new possibilities for next-generation devices and circuits. Here, enhancement-mode (E-mode, remaining off state at zero gate voltages) carbon nanotube (CNT) complementary metal-oxide-semiconductor (CMOS) thin-film transistors (TFTs) are built on paper substrates through a printing-based process. Benefitting from the CMOS circuit style and E-mode transistors, the fabricated CMOS inverters exhibit high voltage gains (more than 11) and noise margins (up to 75% 1/2 VDD at VDD of 0.4 V), and rail-to-rail operation down to a VDD as low as 0.2 V and record low power dissipation as low as 0.0124 pW µm-1 . Furthermore, the transistors and integrated circuits (ICs) show an excellent radiation tolerance of a total ionizing dose (TID) exceeding 2 Mrad with a high dose rate of 365 rad s-1 . The record power consumption and outstanding radiation tolerance behavior achieved in paper-based and easy-to-process CNT electronics are attractive for emerging energy-saving and environmentally friendly ICs in harsh environment (such as outer-space) applications.

14.
Adv Sci (Weinh) ; 9(29): e2203305, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35986431

RESUMO

Microwaves have become a promising wireless driving strategy due to the advantages of transmissivity through obstacles, fast energy targeting, and selective heating. Although there are some studies on microwave powered artificial muscles based on different structures, the lack of studies on microwave control has limited the development of microwave-driven (MWD) robots. Here, a far-field MWD parallel robot controlled by adjusting energy distribution via changing the polarization direction of microwaves at 2.47 GHz is first reported. The parallel robot is based on three double-layer bending actuators composed of wave-absorbing sheets and bimetallic sheets, and it can implement circular and triangular path at a distance of 0.4 m under 700 W transmitting power. The thermal response rate of the actuator under microwaves is studied, and it is found that the electric-field components can provide a faster thermal response at the optimal length of actuator than magnetic-field components. The work of the parallel robot is demonstrated in an enclosed space composed of microwave-transparent materials. This developed method demonstrates the multi-degree-of-freedom controllability for robots using microwaves and offers potential solutions for some engineering cases, such as pipeline/reactors inspection and medical applications.


Assuntos
Micro-Ondas , Robótica , Calefação/métodos , Campos Magnéticos , Músculos
15.
Nanoscale ; 14(12): 4679-4689, 2022 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-35262537

RESUMO

The low resolution of current printing technology (usually 10-100 µm) limits the number of printed thin film transistors (TFTs) per processable area, resulting in the low integration of printed circuits. In this work, we developed a three-dimensional (3D) integration technology to increase the integration of printed TFTs and firstly achieved printed 3D single-walled carbon nanotube (SWCNT) PMOS inverter arrays on the flexible substrates. The flexible 3D PMOS inverter consists of a bottom-gate SWCNT TFT (i.e., a driving TFT) and a top-gate SWCNT TFT (i.e., a load TFT). Printed SWCNT TFTs exhibited good electrical properties with high carrier mobility (up to 9.53 cm2 V-1 s-1), high Ion/Ioff ratio (105-106), low hysteresis, and small subthreshold swing (SS) (70-80 mV dec-1). As-prepared 3D PMOS inverters exhibited rail-to-rail voltage output characteristics, high voltage gain (10) at a low operating voltage (VDD < 1 V), and good mechanical flexibility. Furthermore, the printed 3D PMOS inverters could be utilized to detect ammonia gases, exhibiting satisfactory stability and recovery rate. It is crucial for realizing high-density, multi-functional printed carbon-based electronic devices and circuits for wearable electronics and the Internet of Things (IoT).

16.
Exp Cell Res ; 414(1): 113082, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35218724

RESUMO

BACKGROUND: Osteosarcoma (OS) is the most common primary bone malignancy. Circular RNAs (circRNAs) have been implicated in OS pathogenesis. In the current study, we explored the precise role of circRNA cyclin dependent kinase 14 (circ-CDK14, hsa_circ_0001721) in OS progression. METHODS: The levels of circ-CDK14, miR-198 and E2F transcription factor 2 (E2F2) were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Cell viability, apoptosis, migration and invasion were determined using the Cell Counting-8 Kit (CCK-8), flow cytometry and transwell assays, respectively. Glucose consumption, lactate production and adenosine triphosphate (ATP) level were gauged using the commercial assay kits. The direct relationship between miR-198 and circ-CDK14 or E2F2 was confirmed by dual-luciferase reporter, RNA pull-down and RNA immunoprecipitation (RIP) assays. Animal studies were used to analyze the role of circ-CDK14 in vivo. RESULTS: Our data revealed that circ-CDK14 was up-regulated and miR-198 was down-regulated in OS tissues and cell lines. Circ-CDK14 silencing suppressed OS cell viability, migration, invasion, and glycolysis and promoted cell apoptosis in vitro, as well as diminished tumor growth in vivo. Mechanistically, circ-CDK14 directly targeted miR-198. Moreover, miR-198 was a functional mediator of circ-CDK14 in regulating OS cell progression in vitro. E2F2 was a direct target of miR-198, and miR-198 overexpression regulated OS cell progression in vitro by down-regulating E2F2. Furthermore, circ-CDK14 regulated E2F2 expression by functioning as a sponge of miR-198 in OS cells. CONCLUSION: Our findings demonstrate the inhibitory effect of circ-CDK14 silencing on OS progression by targeting the miR-198/E2F2 axis, establishing a strong rationale for decreasing circ-CDK14 as a novel therapeutic strategy for OS.


Assuntos
Neoplasias Ósseas , MicroRNAs , Osteossarcoma , Animais , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Osteossarcoma/metabolismo , RNA Circular/genética
17.
Sci Rep ; 12(1): 1310, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35079059

RESUMO

Epigallocatechin gallate (EGCG) has the effect to protect skin from ultraviolet B (UVB) induced damages, but it is unstable under ambient conditions, being susceptible to become brown in color. Gallocatechin gallate (GCG), an epimer counterpart of EGCG, is more stable chemically than EGCG. The potential effects of GCG against UVB-induced skin damages has not been available. The objective of this study was to investigate the protective effects of GCG against UVB-induced skin photodamages. GCG was topically applied on the skin of hairless mice at three dosage levels (LL, 12.5 mg/mL; ML 25 mg/mL; HL, 50 mg/mL), with EGCG and a commercially available baby sunscreen lotion SPF50 PA+++ as control. The mice were then irradiated by UVB (fluence rate 1.7 µmol/m2 s) for 45 min. The treatments were carried out once a day for 6 consecutive days. Skin measurements and histological studies were performed at the end of experiment. The results show that GCG treatments at ML and HL levels inhibited the increase in levels of skin oil and pigmentation induced by UVB irradiation, and improved the skin elasticity and collagen fibers. GCG at ML and HL levels inhibited the formation of melanosomes and aberrations in mitochondria of UVB-irradiated skin in hairless mice. It is concluded that GCG protected skin from UVB-induced photodamages by improving skin elasticity and collagen fibers, and inhibiting aberrations in mitochondria and formation of melanosomes.


Assuntos
Catequina/análogos & derivados , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Protetores Solares/administração & dosagem , Raios Ultravioleta/efeitos adversos , Administração Cutânea , Animais , Catequina/administração & dosagem , Feminino , Masculino , Melanossomas/efeitos dos fármacos , Melanossomas/efeitos da radiação , Camundongos , Camundongos Pelados , Camundongos Endogâmicos BALB C , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/efeitos da radiação , Vaselina/administração & dosagem , Doses de Radiação
18.
Small Methods ; 5(8): e2100263, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34927859

RESUMO

Additive printing techniques have been widely investigated for fabricating multilayered electronic devices. In this work, a layer-by-layer printing strategy is developed to fabricate multilayered electronics including 3D conductive circuits and thin-film transistors (TFTs) with low-temperature catalyzed, solution-processed SiO2 (LCSS) as the dielectric. Ultrafine, ultrasmooth LCSS films can be facilely formed at 90 °C on a wide variety of organic and inorganic substrates, offering a versatile platform to construct complex heterojunction structures with layer-by-layer fashion at microscale. The high-resolution 3D conductive circuits formed with gold nanoparticles inside the LCSS dielectric demonstrate a high-speed response to the transient voltage in less than 1 µs. The TFTs with semiconducting single-wall carbon nanotubes can be operated with the accumulation mode at a low voltage of 1 V and exhibit average field-effect mobility of 70 cm2  V-1  s-1 , on/off ratio of 107 , small average hysteresis of 0.1 V, and high yield up to 100% as well as long-term stability, high negative-gate bias stability, and good mechanical stability. Therefore, the layer-by-layer printing strategy with the LCSS film is promising to assemble large-scale, high-resolution, and high-performance flexible electronics and to provide a fundamental understanding for correlating dielectric properties with device performance.

19.
J Nanosci Nanotechnol ; 21(12): 5890-5895, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34229783

RESUMO

ScPO4:Eu3+, Tb3+ phosphors with tuned emission color were prepared through high temperature solid-state reaction. The structure, morphology and photoluminescence properties of the title samples were collected by XRD, SEM and fluorescence spectrophotometer, respectively. Co-doping Eu3+ and Tb3+ in ScPO4 does not change the body-centered tetragonal structure of the host. And the morphology remains essentially unchanged except for slight agglomeration. Changing the ratio of Tb3+/Eu3+, the tuned emission can be achieved, the color could be adjusted from green through yellow to orange-red. The ScPO4:0.03Tb3+, 0.03Eu3+ phosphor with high thermal stability as the single matrix phosphor can be suitable for the NUV-pumped white LED. The white LED with a color rendering index of 86.5 and a correlated color temperature of 3470 K has been generated by packaging BAM:Eu2+ with ScPO4:0.03Tb3+, 0.03Eu3+ on an NUV-InGaN chip.


Assuntos
Európio , Luminescência
20.
Polymers (Basel) ; 13(5)2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33806452

RESUMO

In this research, by utilizing the Very-High-Bond (VHB) 4905 elastomer, we carry out an experimental examination on the humidity effect on dynamic electromechanical performances of dielectric elastomers, including the dynamic response and viscoelastic creeping. Firstly, we experimentally analyze effects of the pre-stretch, peak voltage, waveform and frequency of the dynamic response of VHB 4905 elastomer under several ambient humidities. In general, the amplitude of dynamic deformation gradually adds up with the increasing humidity. Besides, it is found that the amplitude affected by different parameters shows diverse sensitivity to humidity. Subsequently, effect of humidity on the viscoelastic creeping of VHB 4905 is explored. The results demonstrate that, subject to different ambient humidities, the viscoelastic creeping under Alternating Current (AC) voltage is similar to that under Direct Current (DC) voltage. Furthermore, the equilibrium position of dynamic viscoelastic creep enlarges gradually with the humidity, regardless of voltage waveforms. For the dielectric elastomer with a pre-stretch ratio of 3, when the humidity increases from 20% to 80%, the increase of average equilibrium position of dynamic viscoelastic creep is larger than 1599%.

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