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1.
J Nanosci Nanotechnol ; 20(3): 1790-1798, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492344

RESUMO

Tungsten oxide microflowers (WO3 MFs) were fabricated by a simple hydrothermal process through adjusting the pH of the solution by HCl. These MFs possess the outer diameters of about 2 µm and are composed of numerous nanoplates with the average pore size of 10.9 nm. Chemiresistive activity of as-fabricated WO3 MFs sensor was attempted towards oxidizing and reducing target gases, revealing a superior selectivity to NO2 with a maximum response of 22.95 (2 ppm NO2) @105 °C compared to other target gases. One of the key features of as-fabricatedWO3 MFs sensor is the lower detection limit of 125 ppb and operating temperature of 105 °C to NO2 with better reproducibility, signifying commercial prospective of the developed sensor materials. Finally, the gas sensing mechanism of WO3 MFs sensor has been proposed.

2.
Nanoscale Res Lett ; 14(1): 360, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792627

RESUMO

Hybrid heterojunctions based on two-dimensional (2D) and conventional three-dimensional (3D) materials provide a promising way toward nanoelectronic devices with engineered features. In this work, we investigated the band alignment of a mixed-dimensional heterojunction composed of transferred MoS2 on ß-Ga2O3([Formula: see text]01) with and without nitridation. The conduction and valence band offsets for unnitrided 2D-MoS2/3D-ß-Ga2O3 heterojunction were determined to be respectively 0.43 ± 0.1 and 2.87 ± 0.1 eV. For the nitrided heterojunction, the conduction and valence band offsets were deduced to 0.68 ± 0.1 and 2.62 ± 0.1 eV, respectively. The modified band alignment could result from the dipole formed by charge transfer across the heterojunction interface. The effect of nitridation on the band alignments between group III oxides and transition metal dichalcogenides will supply feasible technical routes for designing their heterojunction-based electronic and optoelectronic devices.

3.
Nanoscale Res Lett ; 14(1): 363, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792629

RESUMO

Amorphous In-Ga-Zn-O (a-IGZO) thin-film transistor (TFT) memories are attracting many interests for future system-on-panel applications; however, they usually exhibit a poor erasing efficiency. In this article, we investigate voltage-polarity-dependent programming behaviors of an a-IGZO TFT memory with an atomic-layer-deposited ZnO charge trapping layer (CTL). The pristine devices demonstrate electrically programmable characteristics not only under positive gate biases but also under negative gate biases. In particular, the latter can generate a much higher programming efficiency than the former. Upon applying a gate bias pulse of +13 V/1 µs, the device shows a threshold voltage shift (ΔVth) of 2 V; and the ΔVth is as large as -6.5 V for a gate bias pulse of -13 V/1 µs. In the case of 12 V/1 ms programming (P) and -12 V/10 µs erasing (E), a memory window as large as 7.2 V can be achieved at 103 of P/E cycles. By comparing the ZnO CTLs annealed in O2 or N2 with the as-deposited one, it is concluded that the oxygen vacancy (VO)-related defects dominate the bipolar programming characteristics of the TFT memory devices. For programming at positive gate voltage, electrons are injected from the IGZO channel into the ZnO layer and preferentially trapped at deep levels of singly ionized oxygen vacancy (VO +) and doubly ionized oxygen vacancy (VO 2+). Regarding programming at negative gate voltage, electrons are de-trapped easily from neutral oxygen vacancies because of shallow donors and tunnel back to the channel. This thus leads to highly efficient erasing by the formation of additional ionized oxygen vacancies with positive charges.

4.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(6): 2024-2029, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31839078

RESUMO

Abstract  Among myeloid leukemias, the acute promyelocytic leukemia (APL) was found to be specifically sensitive to all-trans retinoic acid (ATRA), almost all APL patients respond to ATRA therapy. The ATRA induces remission of APL patients by stimulating the differentiation of the leukemia cells. However, with the long-term application of ATRA alone, ATRA resistance has become one of the main causes of chemotherapy failure in the patients with acute promyelocytic leukemia. At present, the mechanism of ATRA-resistance is not completely clear, this review discusses the mechanism of drug-resistance in terms of signal pathways, genes, proteins and enzyme.


Assuntos
Leucemia Promielocítica Aguda , Antineoplásicos , Diferenciação Celular , Humanos , Tretinoína
5.
Ying Yong Sheng Tai Xue Bao ; 30(10): 3563-3571, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31621244

RESUMO

We monitored the type and content of airborne pollen in Haidian District, Beijing City from 2012 to 2016 by the gravity precipitation method, and analyzed the variety of pollen, peak distribution features and changes of its content, and discontinuous variation of concentration. Multiple time scale analysis was carried out for pollen concentration by the ensemble empirical mode decomposition method (EEMD). The relationship between pollen concentration and meteorological factors was analyzed. The results indicated that during the research period, the main types of airborne pollen changed. Woody plants such as Cupressaceae and Salicaceae instead of herbaceous plants contributed the most content of pollen. There was no significant change of the yearly peak distribution of pollen concentration. The concentration in recent five years reduced, while the concentration of herbaceous plants (such as Scolopacjdae) increased. During the statistics period, pollen concentration showed discontinuous changes in early April, late May and early August. Pollen concentration had the change cycle of quasi 2 d, quasi 51 d and quasi 128 d. Among all meteorological factors, temperature played a dominant role in driving the concentration, which may significantly rise during 16 to 18 ℃. The impact of temperature changes on the daily concentration may be delayed and continuous; it is often highly related to the concentration 2-7 d later. Sunshine duration and wind speed had the most significant impact on daily pollen concentration.


Assuntos
Poluentes Atmosféricos , Pequim , China , Cidades , Monitoramento Ambiental , Conceitos Meteorológicos , Pólen , Estações do Ano
6.
Nanoscale Res Lett ; 14(1): 275, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31414235

RESUMO

The Al-doped effects on the band offsets of ZnO/ß-Ga2O3 interfaces are characterized by X-ray photoelectron spectroscopy and calculated by first-principle simulations. The conduction band offsets vary from 1.39 to 1.67 eV, the valence band offsets reduce from 0.06 to - 0.42 eV, exhibiting an almost linear dependence with respect to the Al doping ratio varying from 0 to 10%. Consequently, a type-I band alignment forms at the interface of ZnO/ß-Ga2O3 heterojunction and the AZO/ß-Ga2O3 interface has a type-II band alignment. This is because incorporating Al into the ZnO would open up the band gaps due to the strong Al and O electron mixing, and the conduction and valence band edges consequently shift toward the lower level.

7.
J Nanosci Nanotechnol ; 19(12): 8135-8142, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31196336

RESUMO

Precisely controlled dimensions of heterostructured ZnO nanorod arrays were grown on micropatterned Au films supported by Si substrate using chemical vapor deposition (CVD). The field emission properties were attributed to pointed nanorods, thickness of catalyst, preferential growth, density, morphology of ZnO and Molybdenum (Mo) decorated ZnO nanorod arrays (Mo/ZnO). The selective restrained heterostructure approach resulted in excellent control over periodicity, location and density of ZnO nanorod arrays. Overall, field emission properties of bare ZnO nanorod arrays showed a low turn-on field of ~4.7 V/µm and a high field enhancement factor (ß) ~1686 to 7.3 V/µm and (ß) ~807 for Mo/ZnO. It was also found that the field emission properties were significantly influenced by densely decorated Mo nanoparticles on as-grown ZnO nanorod arrays.

8.
Trials ; 20(1): 343, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182140

RESUMO

BACKGROUND: Spleen qi deficiency (SQD), a syndrome based on traditional Chinese medicine (TCM) theory, is common in patients after radical gastrectomy. SQD manifests with chronic gastrointestinal disorders and systemic symptoms and is challenging to manage. Hou Gu Mi Xi (HGMX) is a dietary TCM formula for SQD. This study aims to evaluate the efficacy and safety of HGMX in patients with SQD who have undergone radical gastrectomy for gastric cancer. METHODS AND DESIGN: This study is a multicenter, randomized, double-blind, placebo-controlled trial. One hundred thirty patients with SQD who have undergone radical gastrectomy for gastric cancer will be assigned to receive either HGMX or placebo for 2 years. The main outcome will be changes in SQD symptoms assessed by the Spleen Qi Deficiency Symptoms Grading and Quantifying Scale. The secondary outcomes will be changes in quality of life assessed by the Short Form 36 scale, performance status as assessed by the Eastern Cooperative Oncology Group Performance Status scale, body weight, and body mass index. Progression-free survival will also be assessed as a secondary outcome. Adverse events (AEs), severe AEs, and study withdrawal due to AEs will be recorded to evaluate the safety of HGMX. DISCUSSION: The results of this trial will provide initial evidence for the use of HGMX as an alternative and complementary intervention to manage chronic postoperative complications in patients who have undergone radical gastrectomy for gastric cancer. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03025152 . Registered on 17 January 2017.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Gastrectomia/efeitos adversos , Medicina Tradicional Chinesa , Complicações Pós-Operatórias/tratamento farmacológico , Qi , Neoplasias Gástricas/cirurgia , Adulto , Idoso , Método Duplo-Cego , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
Nanoscale Res Lett ; 14(1): 181, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31144185

RESUMO

The effect of nitridation treatment on the band alignment between few-layer MoS2 and HfO2 has been investigated by X-ray photoelectron spectroscopy. The valence (conduction) band offsets of MoS2/HfO2 with and without nitridation treatment were determined to be 2.09 ± 0.1 (2.41 ± 0.1) and 2.34 ± 0.1 (2.16 ± 0.1) eV, respectively. The tunable band alignment could be attributed to the Mo-N bonding formation and surface band bending for HfO2 triggered by nitridation. This study on the energy band engineering of MoS2/HfO2 heterojunctions may also be extended to other high-k dielectrics for integrating with two-dimensional materials to design and optimize their electronic devices.

10.
Nanoscale Res Lett ; 14(1): 122, 2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30941527

RESUMO

Electrical characteristics of amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) are compared by using O2 plasma-enhanced atomic layer deposition Al2O3 dielectrics at different temperatures. High-performance a-IGZO TFTs are demonstrated successfully with an Al2O3 dielectric deposited at room temperature, which exhibit a high field-effect mobility of 19.5 cm2 V- 1 s- 1, a small subthreshold swing of 160 mV/dec, a low threshold voltage of 0.1 V, a large on/off current ratio of 4.5 × 108, and superior negative and positive gate bias stabilities. This is attributed to the hydrogen-rich Al2O3 dielectric deposited at room temperature in comparison with higher deposition temperatures, thus efficiently passivating the interfacial states of a-IGZO/Al2O3 and the oxygen vacancies and improving conductivity of the a-IGZO channel by generating additional electrons because of enhanced hydrogen doping during sputtering of IGZO. Such an extremely low thermal budget for high-performance a-IGZO TFTs is very attractive for flexible electronic application.

11.
Nanoscale Res Lett ; 14(1): 76, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30830476

RESUMO

For advanced Cu interconnect technology, Co films have been widely investigated to serve as the liner and seed layer replacement because of a better wettability to Cu than Ta. In this article, the Co films are grown by plasma-enhanced atomic layer deposition using Co(EtCp)2 as a precursor, and the influences of process parameters on the characteristics of the Co films are elaborately investigated. The results indicate that the process window is 125-225 °C with a growth rate of ~ 0.073 Å/cycle. That is to say, the connection of Et group to Cp ligand can enable a stable film growth at 125 °C, while the corresponding temperature must be higher than 200 °C in terms of Co(Cp)2 and Co(MeCp)2. The deposited films contain N and O elements besides dominant Co and C. Furthermore, the prolongation of the NH3 pulse time significantly enhances the conductivity of the Co film and a low resistivity of 117 µΩ cm can be achieved with a NH3 pulse time of 40 s. The root mean square roughness shows a smaller variation with the deposition temperature and maintains a low value of ~ 0.3 nm, indicative of a flat Co film.

12.
Nanoscale Res Lett ; 14(1): 53, 2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30742246

RESUMO

For metal-insulator-metal (MIM) capacitors applicated in the fields of RF, DRAM, and analog/mixed-signal integrated circuits, a high capacitance density is imperative with the downscaling of the device feature size. In this work, the microwave annealing technique is investigated to enhance the dielectric characteristics of Al2O3/ZrO2/Al2O3 based MIM capacitors. The results show that the permittivity of ZrO2 is increased to 41.9 (~ 40% enhanced) with a microwave annealing at 1400 W for 5 min. The substrate temperature is lower than 400 °C, which is compatible with the back end of line process. The leakage current densities are 1.23 × 10-8 and 1.36 × 10-8 A/cm2 for as-deposited sample and 1400 W sample, respectively, indicating that the leakage property is not deteriorated. The conduction mechanism is confirmed as field-assisted tunneling.

13.
J Virol Methods ; 266: 34-40, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30677463

RESUMO

Goose parvovirus (GPV) is one of the most serious viral pathogens in goslings. Recently, a new pathogen to the Chinese mainland-duck-origin novel goose parvovirus (N-GPV)-was found to be 90.8-94.6% identical to the nucleotide sequence of GPV, and typically causes growth disorders and high infection rates in meat ducks. The spread of both of these viruses hinders the healthy development of the waterfowl breeding industry. In this study, recombinase polymerase amplification (RPA) was combined with a vertical flow (VF) visualization strip to develop a universal assay for the rapid detection of GPV and N-GPV. A set of specific primers and probes were designed to target the VP3 gene. Detection was possible at a constant temperature of 37 °C within 5-10 min. The assay successfully detected GPV and N-GPV with high-specificity and did not exhibit cross-reactivity with other waterfowl viruses and bacteria. The analytical sensitivity of the GPV-RPA-VF assay was 2 × 102 copies of GPV plasmid. Validation of the GPV-RPA-VF assay-using 60 samples from the field--confirmed 100% similarity between the results of GPV-RPA-VF and conventional qPCR. The results indicate that the GPV-RPA-VF assay was accurate, sensitive, and specific. This assay can be performed with minimal equipment and training to rapidly detect GPV and N-GPV during the early phase of an outbreak, especially when timely veterinary diagnoses are needed in the field and in rural areas.

14.
Nat Prod Res ; 33(17): 2490-2497, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29631433

RESUMO

Two new labdane diterpenoids, Leojaponin E (1) and F (2), together with three known compounds were isolated from the dried herb of Leonurus japonicus Houtt., Lamiaceae. Their structures were determined based on extensive spectroscopic analyses. The absolute configurations of 1 and 2 were elucidated on the basis of experimental and calculated electronic circular dichroism spectra. In addition, compounds 1 and 2 exerted inhibition of LPS-induced PGE2 production in a dose-dependent manner at concentrations ranging from 5 to 20 µM.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Diterpenos/química , Diterpenos/farmacologia , Leonurus/química , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Dicroísmo Circular , Dinoprostona/biossíntese , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Lipopolissacarídeos/farmacologia , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Componentes Aéreos da Planta/química , Células RAW 264.7
15.
ACS Appl Mater Interfaces ; 11(1): 747-752, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30525419

RESUMO

On-chip supercapacitors have attracted considerable attention because of their high power density, long cycling life, and compatibility with integrated circuits. One critical drawback that restricts their practical application is the low energy density. In this work, low-resistivity mesoporous silicon with a high aspect ratio is prepared by Pt film-assisted chemical etching and utilized as the scaffold of the supercapacitors. Subsequently, low-resistivity (<0.0015 Ω·cm) and ultrathin In2O3 films are coated on the mesoporous silicon scaffold by atomic layer deposition at 200 °C, serving as the active electrode material. The electrochemical measurements reveal that the coating of the In2O3 film remarkably improves the performance of the supercapacitors compared with those without the In2O3 coating. The supercapacitors with a 4.5 nm In2O3 film coating exhibit a capacitance density of 1.36 mF/cm2 at a scan rate of 10 mV/s as well as a better stability against the scan rate. In addition, it is found that the pristine mesoporous silicon walls are collapsed after 400 times of sweeping while those with the In2O3 film coating are still intact even after 2000 times of sweeping. Meanwhile, a high energy density is also achieved without sacrificing the power performance.

16.
Int Urol Nephrol ; 51(2): 201-206, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30542945

RESUMO

OBJECTIVES: To compare two different treatment strategies, one-stage and two-stage multi-tract mini-percutaneous nephrolithotomy (mt-mPCNL), for pediatric complex renal calculus disease. METHODS: Between the period of July 2016 and July 2018, a total of 36 children aged 15 years and younger, with complex renal calculi disease, who underwent total ultrasound-guided mt-mPCNL by a single experienced urologist were enrolled in our study. All patients were assigned either to Group 1 (n = 18) who received one-stage mt-mPCNL or Group 2 (n = 18) who received planned two-stage mt-mPCNL. RESULTS: The demographic data were comparable between the two groups. There were no serious complications (Modified Clavien Grade ≥ III) observed in either group. The stone -free rate (SFR), operation time, postoperative creatinine increase, and perioperative complication rates were similar in both groups (P = 0.603, 0.818, 0.161, and 0.402, respectively). The postoperative hospital stay (5.8 days vs. 7.4 days) and cost (17373.3 CNY vs. 23717.1 CNY) were statistically less in Group 1. Group 2 had significantly less total estimated blood loss (70.6 ml vs. 130.0 ml, P < 0.001). The operation time of two cases in Group 1 with perioperative sepsis or systemic inflammatory response syndrome (SIRS) was more than two hours. CONCLUSIONS: Our preliminary results indicated that both one-stage and two-stage mt-mPCNL were safe and effective for pediatric complex renal calculi. Two-stage mt-mPCNL could significantly reduce blood loss; while one-stage mt-mPCNL could significantly decrease the length and costs of hospitalization. We also suggest that the planned two-stage mt-mPCNL should be applied in children with estimated operation time more than two hours.


Assuntos
Perda Sanguínea Cirúrgica , Cálculos Renais , Nefrolitotomia Percutânea , Complicações Pós-Operatórias , Síndrome de Resposta Inflamatória Sistêmica , Adolescente , Perda Sanguínea Cirúrgica/prevenção & controle , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Criança , China/epidemiologia , Pesquisa Comparativa da Efetividade , Feminino , Humanos , Cálculos Renais/diagnóstico , Cálculos Renais/fisiopatologia , Cálculos Renais/cirurgia , Tempo de Internação/estatística & dados numéricos , Masculino , Nefrolitotomia Percutânea/efeitos adversos , Nefrolitotomia Percutânea/métodos , Duração da Cirurgia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Síndrome de Resposta Inflamatória Sistêmica/diagnóstico , Síndrome de Resposta Inflamatória Sistêmica/epidemiologia , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Ultrassonografia de Intervenção/métodos
17.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 26(6): 1876-1880, 2018 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-30501738

RESUMO

The main physiological function of megakaryocytes is the production of platelets, whose development, maturation and platelet production are a complex regulatory process, and are involved in many factors. In recent years it was found that the lung is also the main site of megakaryocyte-producing platelets in addition to bone marrow. Based on the findings of recent years, this review summarizes the process of megakaryocyte development, maturation and platelet production, with emphasis on the analyzing the regulatory effects of apoptotic factors, miRNA, thrombopoietin and its receptors, interleukins, transcription factors and their corresponding signal pathways on platelet production. To understand the regulatory mechanism of platelet production can help to understand the pathological mechanism of platelet-related diseases and provide new ideas for the diagnosis and treatment of platelet-related diseases.


Assuntos
Megacariócitos , Trombopoese , Plaquetas , Células da Medula Óssea , Trombopoetina
18.
Nanoscale Res Lett ; 13(1): 412, 2018 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-30584649

RESUMO

The energy band alignment of ZnO/ß-Ga2O3 ([Formula: see text]) heterojunction was characterized by X-ray photoelectron spectroscopy (XPS). The ZnO films were grown by using atomic layer deposition at various temperatures. A type-I band alignment was identified for all the ZnO/ß-Ga2O3 heterojunctions. The conduction (valence) band offset varied from 1.26 (0.20) eV to 1.47 (0.01) eV with the growth temperature increasing from 150 to 250 °C. The increased conduction band offset with temperature is mainly contributed by Zn interstitials in ZnO film. In the meanwhile, the acceptor-type complex defect Vzn + OH could account for the reduced valence band offset. These findings will facilitate the design and physical analysis of ZnO/ß-Ga2O3 relevant electronic devices.

20.
ACS Nano ; 12(11): 11203-11210, 2018 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30299925

RESUMO

External stimuli-controlled phase transitions are essential for fundamental physics and design of functional devices. Charge density wave (CDW) is a metastable collective electronic phase featured by the periodic lattice distortion. Much attention has been attracted to study the external control of CDW phases. Although much work has been done in the electric-field-induced CDW transition, the study of the role of Joule heating in the phase transition is insufficient. Here, using the Raman spectroscopy, the electric-field-driven phase transition is in situ observed in the ultrathin 1T-TaS2. By quantitative evaluation of the Joule heating effect in the electric-field-induced CDW transition, it is shown that Joule heating plays a secondary role in the nearly commensurate (NC) to incommensurate (IC) CDW transition, while it dominants the IC-NC CDW transition, providing a better understanding of the electric field-induced phase transition. More importantly, at room temperature, light illumination can modulate the CDW phase and thus tune the frequency of the ultrathin 1T-TaS2 oscillators. This light tunability of the CDW phase transition is promising for multifunctional device applications.

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