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1.
Zhonghua Nei Ke Za Zhi ; 62(12): 1451-1457, 2023 Dec 01.
Artigo em Zh | MEDLINE | ID: mdl-38044072

RESUMO

Objective: To investigate the effect of image quality, degree of stenosis, calcification, and their first-order interactions on diagnostic performance of coronary computed tomography (CT) angiography-derived fractional flow reserve (CT-FFR). Methods: This is a reanalysis of data from a multi-center retrospective cross-sectional study of CT-FFR in China. A total of 522 patients with suspected or known coronary heart disease [mean age: 61.6 (34.0-83.0) years, 71.8% (354/493) were male] from 11 medical centers including the General Hospital of Eastern Theater Command from May 2015 to October 2019 were enrolled. All patients underwent coronary CT angiography (CCTA), CT-FFR, and invasive FFR examination. Subjective image quality scores of target vessels were recorded on CCTA images, and stenosis was visually assessed at the lesion level. Calcification arc and calcification remodeling index (CRI) were recorded for each lesion. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were compared. Two-way analysis of variance was used to analyze the first-order interaction effects of image quality, degree of stenosis, and calcification. Results: A total of 493 patients with 629 lesions with invasive FFR as a reference were included in the study. The overall sensitivity, specificity, and accuracy of CT-FFR were 80.4%, 93.8%, and 88.6%, respectively. The specificity (95.0% vs. 87.3%, χ2=4.11, P=0.043); accuracy (90.1% vs. 81.9%, χ2=6.22, P=0.013); and NPV (89.7% vs. 80.9%, χ2=4.25, P=0.039) of the group with image quality ≥3 was higher than the group with image quality <3. The degree of stenosis affected the sensitivity, PPV, and NPV of CT-FFR and the calcification arc affected the specificity of CT-FFR (all P>0.05). The specificity (95.8% vs. 90.5%, χ2=4.23, P=0.040); accuracy (91.0% vs. 86.1%, χ2=4.01, P=0.045); and NPV (91.1% vs. 83.8%, χ2=5.10, P=0.024) of the group with CRI<1 were higher than that of the group with CRI≥1. In the subgroup of mild and severe stenosis, no calcification, and CRI<1, the accuracy of CT-FFR with image quality ≥3 points were higher than that with image quality <3 points. The accuracy of CT-FFR in the moderate stenosis group was mainly affected by CRI; the accuracy of CT-FFR in the group with CRI<1 was higher than that in the group with CRI≥1 (after Bonferroni correction, P values between groups were statistically significant). Conclusion: Subjective image quality, degree of stenosis, calcification of lesions, and their first-order interactions can all negatively affect the diagnostic performance of CT-FFR.


Assuntos
Calcinose , Doença da Artéria Coronariana , Estenose Coronária , Reserva Fracionada de Fluxo Miocárdico , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Angiografia por Tomografia Computadorizada/métodos , Estenose Coronária/diagnóstico por imagem , Estudos Retrospectivos , Constrição Patológica , Estudos Transversais , Angiografia Coronária/métodos , Tomografia Computadorizada por Raios X , Valor Preditivo dos Testes , Doença da Artéria Coronariana/diagnóstico por imagem
2.
Zhonghua Yi Xue Za Zhi ; 102(32): 2489-2494, 2022 Aug 30.
Artigo em Zh | MEDLINE | ID: mdl-36008318

RESUMO

Objective: To evaluate the incidence of thromboembolism in a cohort of patients with lung cancer who received immune checkpoint inhibitors (ICIs), and explore relevant clinical risk factors. Methods: We retrospectively collected and analyzed the clinical data of patients with confirmed primary lung cancer and treated with ICIs between March 2018 and June 2021 at three hospitals in China (Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology, Fudan University Shanghai Cancer Center and Zhongshan Hospital of Fudan University). The cumulative incidence and risk factors of thromboembolism in these patients were analyzed using a competitive risk model. Results: A total of 804 patients were enrolled, there were 623 males and 181 females, with a median age of 59 years (ranged 28-86 years). Of these, 62 patients encountered 65 thromboembolic events, including 51 venous thromboembolism events (VTE) and 14 arterial thromboembolism events. The cumulative incidence of thromboembolism events at 3, 6, 12 and 24 months were 4.3%, 6.1%, 10.1% and 16.8%, respectively. And the cumulative incidence of venous thromboembolism events at 3, 6, 12 and 24 months were 3.4%, 4.7%, 9.0% and 13.3%, respectively. Multivariate analysis showed that history of thromboembolism (HR=6.345, 95%CI: 2.917-13.802,P<0.001),liver metastasis (HR=2.249, 95%CI: 1.123-4.502,P=0.022) and peripherally inserted central venous catheter (HR=3.674, 95%CI: 1.751-7.712, P<0.001) were independent risk factors for venous thromboembolism during ICIs therapy in patients with lung cancer. Conclusions: Patients with lung cancer under ICIs therapy are at high risk of thromboembolism. And history of thromboembolism, liver metastasis and peripherally inserted central venous catheter are risk factors of venous thromboembolism.


Assuntos
Neoplasias Hepáticas , Neoplasias Pulmonares , Tromboembolia Venosa , Adulto , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Humanos , Imunoterapia , Incidência , Neoplasias Pulmonares/complicações , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Tromboembolia Venosa/epidemiologia
3.
Appl Opt ; 58(3): 704-711, 2019 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-30694258

RESUMO

Plasmonic color filters, exhibiting great promise as an alternative for existing colorant-based filters, often only output one fixed color. Developing active color filters with controllable color output will lead to more compact color filter-based devices. In this paper, we present an approach to achieve active color filtering with a polarization-dependent plasmonic structural color filter, which comprises arrays of asymmetric cross-shaped nanoapertures in an ultrathin film of silver. A systematical study for aperture size, array period, and the thickness of silver film dependences of color filter properties is carried out, and strategies for polarization-dependent color filter designing are generated. A polarization-dependent and high tunability of color can be achieved by selecting the appropriate nanostructure parameters, which imply many potential applications.

4.
Nanotechnology ; 28(8): 085203, 2017 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-28054513

RESUMO

We develop reflective color filters with randomly distributed nanodisks and nanoholes fabricated with hydrogen silsesquioxane and Ag films on silicon substrate. They exhibit high resolution, angle-independence and easily up-scalable fabrication, which are the most important factors for color filters for industrial applications. We uncover the underlying mechanism after systematically analyzing the localized surface plasmon polariton coupling in the electric-field distribution. The agreement of the experimental results with those from the simulation indicates that tunable colors across the visible spectrum can be obtained by simply varying the diameter of the nanodisks, promoting their applications.

5.
J Chem Phys ; 147(14): 144503, 2017 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-29031246

RESUMO

The composition and temperature dependence of static and dynamic structures in NixNb1-x (x = 50-70 at. %) were systematically studied using molecular dynamics with a new-released semi-empirical embedded atom method potential by Mendelev. The calculated pair correlation functions and the structure factor match well with the experimental data, demonstrating the reliability of the potential within relatively wide composition and temperature ranges. The local atomic structures were then characterized by bond angle distributions and Voronoi tessellation methods, demonstrating that the icosahedral ⟨0,0,12,0⟩ is only a small fraction in the liquid state but increases significantly during cooling and becomes dominant at 300 K. The most abundant clusters are identified as ⟨0,0,12,0⟩ and distorted icosahedron ⟨0,2,8,2⟩. The large fraction of these two clusters hints that the relatively good glass forming ability is near the eutectic point. Unlike Cu-Zr alloys, both the self-diffusion coefficient and shear viscosity are insensitive to compositions upon cooling in Ni-Nb alloys. The breakdown of the Stokes-Einstein relation happens at around 1.6Tg (Tg: glass transition temperature). In the amorphous state, the solid and liquid-like atoms can be distinguished based on the Debye-Waller factor ⟨u2⟩. The insensitivity of the dynamic properties of Ni-Nb alloys to compositions may result from the relatively simple solidification process in the phase diagram, in which only one eutectic point exists in the studied composition range.

7.
Appl Opt ; 55(1): 148-52, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26835634

RESUMO

We demonstrate a TE/TM polarization-independent plasmonic subtractive color filtering scheme employing ultrathin two-dimensional Ag nanodisks. These TE/TM polarization-independent subtractive color filters exhibit small feature sizes (below 200 nm) and high transmission up to 70% in the visible spectral region, superior to previously reported plasmonic color filters. Simulated optical transmission spectra and colors are in good agreement with experimental results. The color-filtering behaviors strongly depend on thickness and period of nanodisks. Underlying mechanisms are also discussed in detail.

8.
Opt Express ; 23(16): 20563-8, 2015 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-26367908

RESUMO

In this work, an ultrafast laser-driven microactuator based on the photoacoustic mechanism was proposed with large amplitude and high response frequency. The microactuator was fabricated by LIGA technology. The displacement of the microactuator could be up to 11 µm at resonance state when the repeat frequency was around 14 kHz using a nanosecond pulse laser. Theoretical model was set up and the calculated results agree reasonably well with the experimental data. The microactuator based on the photoacoustic mechanism provides a more efficient actuation method.

9.
Nanotechnology ; 26(30): 305204, 2015 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-26160906

RESUMO

Plasmonic subtractive color filters through patterning periodic nanostructures on ultrathin Ag films deposited on a glass substrate, exhibiting good durability, simple fabrication, and flexible color tunability, have attracted considerable attention due to their tremendous potential applications. While previous studies have mainly focused on their extraordinary physical mechanisms, color purity, which is another key parameter for high quality imaging applications, has been much less investigated. In this work, we demonstrate that the relative position of nanoholes patterned on ultrathin Ag films can largely affect the color purity of plasmonic subtractive color filters. The calculated results agree reasonably well with the experimental data, revealing that the purity of subtractive colors can be improved by changing the nanohole arrays from square lattice to triangular lattice without reducing transmission at visible frequencies. In addition, underlying mechanisms are clarified by systematically analyzing the dominant valley in transmission spectra.

10.
Appl Opt ; 54(6): 1369-73, 2015 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-25968201

RESUMO

This work presents the design, modeling, simulation, and characterization of a metal bent-beam photo-thermal micro-actuator. The mechanism of actuation is based on the thermal expansion of the micro-actuator which is irradiated by a laser, achieving noncontact control of the power supply. Models for micro-actuators were established and finite-element simulations were carried out to investigate the effects of various parameters on actuation properties. It is found that the thermal expansion coefficient, thermal conductivity, and the geometry size largely affected actuation behavior whereas heat capacity, density, and Young's modulus did not. Experiments demonstrated the dynamic properties of a Ni micro-actuator fabricated via LIGA technology with 1100/30/100 µm (long/wide/thick) arms. The tip displacement of the micro-actuator could achieve up to 42 µm driven by a laser beam (1064 nm wavelength, 1.2 W power, and a driving frequency of 1 HZ). It is found that the tip displacement decreases with increasing laser driving frequency. For 8 Hz driving frequency, 17 µm (peak-valley value) can be still reached, which is large enough for the application as micro-electro-mechanical systems. Metal photo-thermal micro actuators have advantages such as large displacement, simple structure, and large temperature tolerance, and therefore they will be promising in the fields of micro/nanotechnology.

11.
Pulm Pharmacol Ther ; 29(1): 15-23, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25018015

RESUMO

UNLABELLED: Leukotriene B4 (LTB4) is a chemotactic mediator implicated in the pathogenesis of asthma. JNJ-40929837 is an oral inhibitor of LTA4 hydrolase, which catalyzes LTB4 production. We evaluated the effects of JNJ-40929837 in a human bronchial allergen challenge (BAC) model. In this double-blind, 3-period crossover study, 22 patients with mild, atopic asthma were randomized to one of three treatments per period: 100 mg/day JNJ-40929837 for 6 days followed by 50 mg/day on day 7; 10 mg/day montelukast for 6 days; and matched placebo. The BAC was performed on day 6 of each treatment period. Primary outcome was BAC-induced late asthmatic response (LAR) measured by maximal percent reduction in forced expiratory volume (FEV1) in one second. Secondary outcomes included early asthmatic response (EAR) by maximal percent reduction in FEV1, EAR and LAR evaluated by area under the FEV1/time curve (AUC0-2, AUC3-10, respectively), change in baseline FEV1 after 5-day treatment, safety, and correlation of JNJ-40929837 to the divalent cation ionophore A23187-stimulated whole blood LTB4 levels and sputum basal LTB4 levels. No significant differences were observed in the primary or secondary FEV1 endpoints with JNJ-40929837 versus placebo. Compared with placebo (n = 17, LS mean = 27.7), there was no significant attenuation of the maximal percent reduction in the LAR FEV1 with JNJ-40929837 (n = 16, LS mean = 28.6, P = 0.63) but montelukast (n = 17, LS mean = 22.6, P = 0.01) significantly attenuated the LAR. JNJ-40929837 substantially inhibited LTB4 production in whole blood, decreased sputum LTB4 levels and was well-tolerated. The number of adverse events leading to study withdrawal was the same in JNJ-40929837 and placebo groups. In conclusion, JNJ-40929837 demonstrated target engagement in blood and sputum. No significant impact in response to allergen inhalation was observed with JNJ-40929837 versus placebo. REGISTRATION: This study is registered at ClinicalTrials.gov: NCT01241422.


Assuntos
Acetatos/farmacologia , Antiasmáticos/farmacologia , Asma/tratamento farmacológico , Epóxido Hidrolases/antagonistas & inibidores , Quinolinas/farmacologia , Tiazóis/farmacologia , Tropanos/farmacologia , Adulto , Antiasmáticos/efeitos adversos , Asma/fisiopatologia , Testes de Provocação Brônquica , Estudos Cross-Over , Ciclopropanos , Método Duplo-Cego , Feminino , Volume Expiratório Forçado , Humanos , Leucotrieno B4/metabolismo , Masculino , Escarro/metabolismo , Sulfetos , Tiazóis/efeitos adversos , Resultado do Tratamento , Tropanos/efeitos adversos , Adulto Jovem
12.
Phys Rev Lett ; 109(10): 105502, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-23005298

RESUMO

The issue, composition dependence of glass-forming ability (GFA) in metallic glasses (MG), has been investigated by systematic experimental measurements coupled with theoretical calculations in Cu-Zr and Ni-Nb alloy systems. It is found that the atomic-level packing efficiency strongly relates to their GFA. The best GFA is located at the largest difference in the packing efficiency of the solute-centered clusters between the glassy and crystal alloys in both MG systems. This work provides an understanding of GFA from atomic level and will shed light on the development of new MGs with larger critical sizes.

13.
Nanotechnology ; 23(7): 075704, 2012 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-22261409

RESUMO

Room temperature ferromagnetism has been observed in freshly synthesized and post-annealed SnO2 nanosheets. The results of x-ray diffraction and x-ray photoelectron spectroscopy reveal that the newly synthesized samples and those annealed at 400 °C under either an O2 or Ar atmosphere possess rutile structure and no other impurity phases are observed. The fitting results of the O 1s and Sn 3d spectra from SnO2 samples annealed at 400 °C under an O2 or Ar atmosphere both indicate that oxygen vacancies inevitably exist in these samples. It is found that the saturation magnetization of all the annealed samples does not feature mono-dependence on oxygen vacancies, whereas an Sn vacancy related origin seems more plausible to account for variations in the magnetization of samples studied. This finding corresponds to first-principle calculation results from our previous work. Furthermore, the Curie temperature of SnO2 nanosheets was estimated to be around 300 °C, rendering it a very good option for the next generation of spintronics.


Assuntos
Imãs/química , Nanoestruturas/química , Compostos de Estanho/química , Nanoestruturas/ultraestrutura , Espectroscopia Fotoeletrônica , Temperatura
14.
Phys Chem Chem Phys ; 14(44): 15547-53, 2012 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-23073153

RESUMO

Composite Ni-YSZ fuel electrodes are able to operate only under strongly reducing conditions for the electrolysis of CO(2) in oxygen-ion conducting solid oxide electrolysers. In an atmosphere without a flow of reducing gas (i.e., carbon monoxide), a composite fuel electrode based on redox-reversible La(0.2)Sr(0.8)TiO(3+δ) (LSTO) provides a promising alternative. The Ti(3+) was approximately 0.3% in the oxidized LSTO (La(0.2)Sr(0.8)TiO(3.1)), whereas the Ti(3+) reached approximately 8.0% in the reduced sample (La(0.2)Sr(0.8)TiO(3.06)). The strong adsorption of atmospheric oxygen in the form of superoxide ions led to the absence of Ti(3+) either on the surface of oxidized LSTO or the reduced sample. Reduced LSTO showed typical metallic behaviour from 50 to 700 °C in wet H(2); and the electrical conductivity of LSTO reached approximately 30 S cm(-1) at 700 °C. The dependence of [Ti(3+)] concentration in LSTO on P(O(2)) was correlated to the applied potentials when the electrolysis of CO(2) was performed with the LSTO composite electrode. The electrochemical reduction of La(0.2)Sr(0.8)TiO(3+δ) was the main process but was still present up to 2 V at 700 °C during the electrolysis of CO(2); however, the electrolysis of CO(2) at the fuel electrode became dominant at high applied voltages. The current efficiency was approximately 36% for the electrolysis of CO(2) at 700 °C and a 2 V applied potential.

15.
Nanotechnology ; 22(30): 305306, 2011 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-21719962

RESUMO

A simple and effective color tuning method has been developed by controlling the pore depth of the metal-coated porous alumina (PA) template. The mechanism for color tuning in this method was uncovered, which can be used to design a colorful complex pattern. A colorful 'world map' was produced and exhibited on a PA template by this method. Such vivid color tuning is predominantly due to the interference enhancement of the nanostructure. This method has the potential for tuning colors and being widely applied in the fields of nanotechnology, physics and photonics.

16.
Nanotechnology ; 22(29): 295708, 2011 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-21680967

RESUMO

A novel erbium-based compound as well as Er(2)O(3) nanosheets have been synthesized through a simple hydrothermal route. The nanosheets are of 200 nm width and 10-15 nm thickness. It is suggested that this erbium-based compound has a possible formula of Er(2)O(5)H(4) with a primitive tetragonal structure (cell parameters: a = 8.465(1) and c = 15.117(2) Å). Face-centered cubic and body-centered cubic structured Er(2)O(3) nanosheets were obtained after calcination of this compound at 623 and 973 K, respectively, both having a paramagnetic behavior. Er(2)O(5)H(4) and Er(2)O(3) nanosheets have similar up-conversion properties with strong blue emission, which is rarely reported in the literature. The existence of absorbed surface contaminations in nanosheets might be the origin for the blue emission enhancement.

17.
Nanotechnology ; 22(15): 155706, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21389574

RESUMO

Size-tunable GeO2 nanocubes were initially prepared by a modified sono-assisted reverse micelle method and then functionalized with an amino-terminated silanizing agent. Subsequently, gold decorated GeO2 nanocomposites were prepared at pH ≈ 7 and 80 °C. It was found that well-dispersed gold nanoparticles on GeO2 nanocubes could be obtained only if gold salt is abundant to favor simultaneous, homogeneous nucleation of gold particles. Additional gold ions were reduced onto these attached 'seed' particles accompanied by synchronous dissolution of water-soluble GeO2 cores, resulting in gold hollow cubic shells. The GeO2 nanocubes and Au/GeO2 nanocomposites as well as gold hollow cubic shells were characterized by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and UV-visible spectroscopy. In particular, gold hollow cubic shells feature a plasmon resonance peak at above 900 nm, which renders it quite promising in biochemical applications.


Assuntos
Germânio/química , Ouro/química , Nanoconchas/química , Água/química , Compostos de Ouro/química , Isocianatos/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanocompostos/química , Tamanho da Partícula , Silanos/química , Solubilidade , Espectrometria por Raios X , Espectrofotometria , Ressonância de Plasmônio de Superfície , Difração de Raios X
18.
J Am Chem Soc ; 132(1): 46-7, 2010 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-20000321

RESUMO

In this communication, we successfully synthesized a new SnO(2) nanoarchitecture: extremely thin sheets, with minimum thicknesses of 1.5-3.0 nm. The products were prepared through a facile hydrothermal treatment using tin dichloride as the precursor. Planar or scrolled SnO(2) sheets were carefully examined by transmission electron microscopy. The assemblies of these sheets have a high BET surface area of 180.3 m(2)/g and extraordinarily large pore volume of 1.028 cm(3)/g. They also exhibit a high lithium storage capacity and excellent cyclability due to its nanometer-sized frame and breathable characteristic.

19.
J Am Chem Soc ; 132(16): 5572-3, 2010 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-20364814

RESUMO

A new tetragonal phase of PbTiO(3) was discovered, in which each TiO(6) octahedron pair shares an edge and stacks over following pairs in an interlaced manner to form a one-dimensional (1D) columned structure along the c-axis. This new tetragonal phase of PbTiO(3) transforms into a normal perovskite phase in air at elevated temperature.

20.
Phys Rev Lett ; 104(10): 105702, 2010 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-20366436

RESUMO

Using high-pressure synchrotron x-ray absorption spectroscopy, we observed the Ce 4f electron in Ce(75)Al(25) metallic glass transform from its ambient localized state to an itinerant state above 5 GPa. A parallel x-ray diffraction study revealed a volume collapse of about 8.6%, coinciding with 4f delocalization. The transition started from a low-density state below 1.5 GPa, went through continuous densification ending with a high-density state above 5 GPa. This new type of electronic polyamorphism in densely packed metallic glass is dictated by the Ce constituent, and is fundamentally distinct from the well-established structural polyamorphism in which densification is caused by coordination change and atomic rearrangement.

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