Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Opt Express ; 31(9): 13923-13932, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37157267

RESUMO

Metasurfaces have exhibited versatile capacities of controlling electromagnetic (EM) waves due to the high degree of freedom of designing artificially engineered meta-atoms. For circular polarization (CP), broadband phase gradient metasurfaces (PGMs) can be realized based on P-B geometric phase by rotating meta-atoms; while for linear polarization (LP), realization of broadband phase gradients has to resort to P-B geometric phase during polarization conversion and polarization purity has to be sacrificed for broadband properties. It is still challenging to obtain broadband PGMs for LP waves without polarization conversion. In this paper, we propose the design of 2D PGMs by combining the inherently wideband geometric phases and non-resonant phases of meta-atom, under the philosophy of suppressing Lorentz resonances that usually bring about abrupt phase changes. To this end, an anisotropic meta-atom is devised which can suppress abrupt Lorentz resonances in 2D for both x- and y-polarized waves. For y-polarized waves, the central straight wire is in perpendicular to electric vector Ein of incident waves, Lorentz resonance cannot be excited although the electrical length approaches or even exceeds half a wavelength. For x-polarized waves, the central straight wire is in parallel with Ein, a split gap is opened on the center of the straight wire so as to avoid Lorentz resonance. In this way, the abrupt Lorentz resonances are suppressed in 2D and the wideband geometric phase and the gradual non-resonant phase are left for broadband PGM design. As a proof of concept, a 2D PGM prototype for LP waves was designed, fabricated and measured in microwave regime. Both simulated and measured results show that the PGM can achieve broadband beam deflection for reflected waves for both x- and y-polarized waves in broadband, without changing the LP state. This work provides a broadband route to 2D PGMs for LP waves and can be readily extended to higher frequencies such as terahertz and infrared regimes.

2.
Opt Express ; 31(23): 37882-37891, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-38017908

RESUMO

Half-wave wall is the most common method of achieving electromagnetic (EM) transparency. Transmission windows can be formed when reflected waves are out of phase. Due to the interference mechanism, these windows are dependent on the frequency and incident angle of EM waves, leading to limited bandwidth, especially under extreme angles. In this letter, we propose to extend the bandwidth of the transmission window under extreme angles by utilizing dispersion. To this end, long metallic wires are embedded into the half-wave wall matrix, without increasing the physical thickness. Due to the plasma-like behavior of metallic wires under TE-polarization, the effective permittivity of the half-wave wall, rather than keeping constant, increases with frequency nonlinearly. Such a dispersion will boost wideband transparency in two aspects. On one hand, an additional transmission window will be generated where the effective permittivity equals that of the air; on the other hand, the 1st- and 2nd-order half-wave windows will be made quite closer. By tailoring the dispersion, the three windows can be merged to enable wideband transparency under extreme incident angles. A proof-of-principle prototype was designed, fabricated, and measured to verify this strategy. Both simulated and measured results show that the prototype can operate in the whole Ku-band under incident angle [70°, 85°] for TE-polarized waves. This work provides an effective method of achieving wideband EM transparency under extreme angles and may find applications in radar, communications, and others.

3.
Opt Express ; 30(5): 7356-7371, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35299500

RESUMO

Factors influencing atmospheric visibility (VIS) in coastal areas are more complex than those for inland and far oceans owing to the complex circulation and aerosol sources. This study analyzed the factors influencing VIS under sea-land breeze circulation (SLBC) for different external aerosol sources based on field survey data in southern Chinese coastal areas. First, SLBC characteristics observed during the experiment period showed that on SLBC days, sea breeze occurs more frequently (∼50%) than land breeze (∼27%), and the wind speed (WS) is generally small, with a mean sea and land breeze WSs of ∼2.18 m/s and ∼2.38 m/s, respectively. Then, analysis of factors influencing VIS was conducted for different land/sea breeze conditions and external aerosol source conditions indicated by the HYSPLIT4 model simulations. Results showed that the aerosol particle number concentration (PNC) and relative humidity (RH) both had negative correlations with VIS, while only very weak relationships between WS and VIS were found, possibly due to small WSs on SLBC days or because local aerosols were not pure marine aerosols. Further two-factor analysis of VIS showed that the power-law function relating VIS with PNC in each RH bin ranges from ∼-0.3 to ∼-1.5, and VIS exhibited sharper exponential decline with increasing PNC under high RH. A new method of retrieving aerosol-extinction hygroscopic growth factor (fext) with the measured VIS, RH, and PNC was developed to investigate the optical hygroscopic growth property of aerosols. Results show that aerosols in the study area have similar fext under different land/sea breeze and external aerosol source conditions; the deliquescence RH of aerosols is ∼60%, suggesting that mainly polluted marine aerosol was observed during experiments in this area.

4.
Opt Express ; 30(5): 7110-7123, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35299481

RESUMO

Structuring elements of gratings brings more freedom in manipulating diffraction waves, e.g., retroreflection using diffraction orders other than the 0th order. Most retroreflective metagratings (RMs) can achieve retroreflection only under one particular direction, limiting their applications. In this paper, we propose a quasi-omnidirectional RM based on wave-vector reversion for TE-polarized waves. The metagrating element is composed of four rotationally-symmetric sub-elements, which is composed of one probe and two directors on its two sides. The substrate-air-metal layer can reverse kz while directors can reverse kx. Therefore, the wave-vector k of reflected waves can be completely reversed by the sub-element, providing necessary momentum for retroreflection. The -2nd diffraction order of the metagrating is tailored to channel out waves with reversed k, leading to retroreflection. Due to the element's four-fold rotational symmetry, retroreflection can be achieved along four directions, covering all of the four quarters of azimuth angle. We demonstrate prototypes in Ku band, and the average backscattering enhancement compared with a metal plane with the same area (SAMP) along the four directions reaches up to 31.3 dB with incident angle 50.0° at 15.0 GHz. Both simulated and measured results verify our design. This work provides another perspective on retroreflection and may find applications in retroreflective functional devices.

5.
Opt Express ; 30(11): 19716-19730, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-36221740

RESUMO

Metasurfaces have provided unprecedented degrees of freedom in manipulating electromagnetic (EM) waves and also granted high possibility of integrating multiple functions into one single meta-device. In this paper, we propose to incorporate the retroreflection function with transmission function by means of metasurface design and then demonstrate a dual-polarization multi-angle retroreflective metasurface (DMRM) with bilateral transmission bands. To achieve high-efficiency retroreflections, the compact bend structures (CBSs), which exhibit high reflections around 10.0 GHz in X band, are added onto the substrate of the DMRM. Two selected metasurface elements are periodically arranged so as to form 0-π-0 phase profile. By delicately adjusting the periodicity, high-efficiency retroreflections can be produced for both TE and TM-polarized waves under both vertical incidence and oblique incident angles ±50.0°, with an average efficiency of 90.2% at the designed frequency. Meanwhile, the two metasurface elements exhibit high transmission properties and minor phase disparities in S, C and Ku bands, resulting in bilateral transmission windows. Prototypes were designed and fabricated. Both simulated and measured results verified our design. This work provides an effective means of integrating retroreflection functions with other functions and may find applications in target tracking, radomes and other sensor integrated devices in higher frequency or even optical frequency bands.

6.
Opt Express ; 29(22): 35238-35246, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34808962

RESUMO

A model for estimating astronomical seeing at Kunlun Station (Dome A, Antarctica) is proposed. This model is based on the Tatarskii equation, using the wind shear and temperature gradient as inputs, and a seeing model depending directly on the weather data is provided. The seeing and near-ground weather data to build and validate the proposed seeing model were measured at Dome A during the summer of 2019. Two calculation methods were tested from the measured weather data relating the wind shear and temperature gradient to a combination of the two levels for the boundary layer. Both methods performed well, with correlation coefficients higher than 0.77. The model can capture the main seeing trends in which the seeing becomes small when weak wind speed and strong temperature inversion occur inside the boundary layer.

7.
J Opt Soc Am A Opt Image Sci Vis ; 38(10): 1483-1488, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34612978

RESUMO

A simple physics-based method for estimating optical turbulence (Cn2) within the surface layer over snow and ice is proposed, using the Tatarski equation with an improved outer scale model. This improved outer scale model mainly requires the calculation of the wind shear and temperature gradients. Based on the measurements from a mobile polar atmospheric parameter measurement system at the Antarctic Taishan Station in 2014, Cn2 was estimated using two methods: the Tatarski equation and the Monin-Obukhov similarity (MOS) theory. Compared with 16 days of measurements from a micro-thermometer, the correlation coefficient of log10(Cn2) estimated by the Tatarski equation is 0.72, which is a slightly more accurate Cn2 variation in trend and magnitude than the MOS theory. The results suggest that this simple method has potential value for the forecasting applications of optical turbulence.

8.
Appl Opt ; 60(14): 4084-4094, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33983160

RESUMO

An optical turbulence ($C_n^2$) was found to be concentrated predominantly in the thin surface layer (SL) above the Antarctic Plateau. We present an estimation of the behavior of the SL $C_n^2$ during the summer time over the entire Antarctic Plateau, using the polar-optimized version of the Weather Research and Forecast model (Polar WRF) coupled with the Monin-Obukhov similarity theory. The results show that the $C_n^2$ is affected by the sunlight direction and terrain height. The $C_n^2$ minimum occurs sometime around the morning and evening transitions, when the condition of neutral stability is achieved inside the SL. These $C_n^2$ minima may be attributed to the relatively weaker thermal convection resulting from a small temperature difference. The simulated $C_n^2$ data coincide well with the measurements taken at the Antarctic Taishan Station using a micro-thermometer and sonic anemometer; the data are also in agreement with the seeing values obtained from a differential image motion monitor. In addition, the Polar WRF captured the $C_n^2$ minimum more precisely compared to the standard WRF.

9.
Opt Express ; 28(25): 37236-37248, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33379562

RESUMO

Spoof surface plasmon polariton (SSPP) is kind of sub-wavelength electromagnetic (EM) mode, which is favorable for miniaturization and thinning of EM devices. In this paper, we propose a method of designing thin planar retro-reflector that can operate under multiple incidence angles at the same frequency. The retro-reflector is composed of a transmissive phase gradient metasurface (TPGM) placed above a metallic patch array (MPA), where the former couples and decouples SSPPs while the latter supports eigen-mode propagation of SSPPs. Under oblique incident angles, the TGPM can impart 0 and π Pancharatnam-Berry (P-B) phases alternatively, producing P-B phase gradients along its surface. Incident waves can be coupled as SSPPs propagating on the MPA which will be reflected at the borders of the MPA, thus the wave-vector of SSPPs is reversed. In this way, retro-reflection can be realized under the two incidence angles θ=±45.0°. Moreover, due to mode mismatch between the TPGM and MPA under normal incidence, the retro-reflector acts like a planar metallic plate under θ=0°. To verify this method, a prototype was designed, fabricated and measured. Both the simulation and measurement results verify significant backscattering enhancement under θ=±45.0° and 0° at 10.0 GHz. This work provides an alternative method of designing planar retro-reflectors and may find applications in wireless communication, target tracking, etc.

10.
Opt Express ; 28(24): 35724-35733, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33379683

RESUMO

Chromatism generally exists in most metasurfaces. Because of this, the deflected angle of metasurface reflectors usually varies with frequency. This inevitably hinders wide applications of metasurfaces to broadband signal scenarios. Therefore, it is of great significance to overcome chromatism of metasurfaces. With this aim, we firstly analyze necessary conditions for achromatic metasurface deflectors (AMD) and deduce the ideal dispersions of meta-atoms. Then, we establish a Self-Organizing Map (SOM) Neural Network as a prepositive model to obtain a diversified searching map, which is then applied to Greedy Algorithm to search meta-atoms with the required dispersions. Using these meta-atoms, an AMD was designed and simulated, with a thickness about 1/15 the central wavelength. A prototype was fabricated and measured. Both the simulation and measurement show that the proposed AMD can achieve an almost constant deflected angle of 22° under normal incidence within 9.5-10.5GHz. This method may find wide applications in designing functional metasurfaces for satellite communications, mobile wireless communications and others.

11.
J Opt Soc Am A Opt Image Sci Vis ; 37(6): 995-1001, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32543601

RESUMO

It is worth highlighting that, for the first time to the best of our knowledge, vertical profiles of atmospheric parameters and $C_n^2$ were measured at Lhasa, south of the Tibetan Plateau, using balloon-borne radiosondes. Based on the measurements, two new statistical models (Lhasa HMN and Lhasa Dewan) for estimating turbulence strength are proposed. Attention has been paid to evaluate the reliability of the two models to reconstruct vertical profiles of $C_n^2$ from a statistical perspective. The statistical analyses presenting the Lhasa HMN model are accompanied with lower bias, root mean square error (RMSE), and bias-corrected RMSE ($\sigma$) than those of the Lhasa Dewan model, which implies the Lhasa HMN model can better reveal the nature of turbulence characteristics of Lhasa influenced by unique local weather conditions. In addition, the comparison between the Lhasa HMN model and measurements in calculating integrated astroclimatic parameters is carried out, and the result suggests that the performance of the Lhasa HMN model is reliable and satisfactory. The new reliable $C_n^2$ model offers new insight into the characteristics of optical turbulence at Lhasa and provides support for pursuing astronomical site selection in the Tibetan Plateau.

12.
Phys Chem Chem Phys ; 20(40): 25780-25791, 2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30283972

RESUMO

Atmospheric aerosols have a tremendous influence on visibility, climate, and human health. New particle formation (NPF) is a crucial source of atmospheric aerosols. At present, certain field observations and experiments have discovered the presence of 3-hydroxy-4,4-dimethylglutaric acid (HDMGA), which may participate in NPF events. However, the nucleation mechanism of HDMGA has not been clearly understood. In addition, dimethylamine (DMA) is an important precursor of nucleation. The nucleation mechanism involving HDMGA and DMA has not been studied. In this study, the most stable structures of (HDMGA)(H2O)n (n = 0-3) and (HDMGA)(DMA)(H2O)n (n = 0-3) were obtained by using M06-2X coupled with the 6-311++G(3df,3pd) basis set. The α-carboxyl group is directly attached to the amino group in all the most stable configurations. Proton transfer enhances the strength of a hydrogen bond, as well as promotes the generation of a global minimum structure. Temperature has a considerable influence on the distribution of isomers for (HDMGA)(DMA)(H2O)3 as compared to the other investigated clusters. The Gibbs free energy values reveal that most of the clusters can exist in NPF, except for (HDMGA)(H2O)1. The process of adding a cluster of (H2O)n more likely occurs in the atmosphere than gradually adding a single water molecule.

13.
J Phys Chem A ; 122(13): 3470-3479, 2018 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-29547296

RESUMO

Ammonia and amines are important common trace atmospheric species that can enhance new particle formation (NPF) in the Earth's atmosphere. However, the synergistic effect of these two bases involving nucleation is still lacking. We studied the most stable geometric structures and thermodynamics of quaternary (NH3)(CH3NH2)(H2SO4) m(H2O) n ( m = 1-3, n = 0-4) clusters at the PW91PW91/6-311++G(3df,3pd) level of theory for the first time. We find that the proton transfer from H2SO4 molecule to CH3NH2 molecule is easier than to NH3 molecule in the free or hydrated H2SO4-base clusters, and thus leads to the stability. The energetically favorable formation of the (NH3)(CH3NH2)(H2SO4) m(H2O) n ( n = 0-4) clusters, by hydration or attachment of base or substitution of ammonia by methylamine at 298.15 K, indicate that ammonia and methylamine together could enhance the stabilization of small binary clusters. At low RH and an ambient temperature of 298.15 K, the concentration of total hydrated (NH3)(CH3NH2)(H2SO4)2 clusters could reach that of total hydrated (NH3)(H2SO4)2 clusters, which is the most stable ammonia-containing cluster. These results indicate that the synergistic effect of NH3 and CH3NH2 might be important in forming the initial cluster with sulfuric acid and subsequently growth process. In addition, the evaporation rates of (NH3)(CH3NH2)(H2SO4)(H2O), (NH3)(CH3NH2)(H2SO4)2 and (NH3)(CH3NH2)(H2SO4)3 clusters, three relative abundant clusters in (NH3)(CH3NH2)(H2SO4) m(H2O) n system, were calculated. We find the stability increases with the increasing number of H2SO4 molecules.

14.
J Virol ; 87(9): 5205-18, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23449794

RESUMO

Picorna-like viruses in the Picornavirales order are a large group of positive-strand RNA viruses that include numerous important pathogens for plants, insects, and humans. In these viruses, nonstructural protein 2C is one of the most conserved proteins and contains ATPase activity and putative RNA helicase activity. Here we expressed 2C protein of Ectropis obliqua picorna-like virus (EoV; genus Iflavirus, family Iflaviridae, order Picornavirales) in a eukaryotic expression system and determined that EoV 2C displays ATP-independent nucleic acid helix destabilizing and strand annealing acceleration activity in a concentration-dependent manner, indicating that this picornaviral 2C is more like an RNA chaperone than like the previously predicted RNA helicase. Our further characterization of EoV 2C revealed that divalent metal ions, such as Mg(2+) and Zn(2+), inhibit 2C-mediated helix destabilization to different extents. Moreover, we determined that EoV 2C also contains ATPase activity like that of other picornaviral 2C proteins and further assessed the functional relevance between its RNA chaperone-like and ATPase activities using mutational analysis as well as their responses to Mg(2+). Our data show that, when one of the two 2C activities was dramatically inhibited or almost abolished, the other activity could remain intact, showing that the RNA chaperone-like and ATPase activities of EoV 2C can be functionally separated. This report reveals that a picorna-like virus 2C protein displays RNA helix destabilizing and strand annealing acceleration activity, which may be critical for picornaviral replication and pathogenesis, and should foster our understanding of picorna-like viruses and viral RNA chaperones.


Assuntos
Adenosina Trifosfatases/metabolismo , DNA Viral/metabolismo , RNA Helicases/metabolismo , Vírus de RNA/enzimologia , RNA Viral/metabolismo , Proteínas não Estruturais Virais/metabolismo , Adenosina Trifosfatases/genética , Sequência de Aminoácidos , DNA Viral/química , DNA Viral/genética , Dados de Sequência Molecular , Conformação de Ácido Nucleico , RNA Helicases/genética , Vírus de RNA/genética , RNA Viral/química , RNA Viral/genética , Alinhamento de Sequência , Proteínas não Estruturais Virais/genética
15.
Mil Med ; 188(3-4): 841-843, 2023 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-35253059

RESUMO

Graves' disease (GD) is the most common cause of hyperthyroidism in the clinic, accounting for about 85% of all hyperthyroidisms. However, hyperthyroidism combined with OH has been rarely reported in the international community. We analyzed the clinical characteristics and pathogenesis of GD combined with orthostatic hypotension. We conducted a retrospective analysis of 2 GD combined with orthostatic hypotension cases diagnosed by Chinese and Western Medical Association Hospital of Southern Medical University from July to August 2018 and discussed their clinical characteristics, treatment methods, and pathogenesis. The main clinical manifestations of both two patients with hyperthyroidism were vertigo during postural changes or activities and relief from supine position and blood volume supplementation. Considering the lack of blood volume, the symptoms were alleviated after symptomatic treatment. The possibility of hyperthyroidism combined with orthostatic hypotension should be taken into consideration in clinical diagnosis and treatment.


Assuntos
Doença de Graves , Hipertireoidismo , Hipotensão Ortostática , Humanos , Estudos Retrospectivos , Hipotensão Ortostática/complicações , Doença de Graves/complicações , Doença de Graves/diagnóstico , Doença de Graves/tratamento farmacológico
16.
ACS Appl Mater Interfaces ; 15(30): 37026-37037, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37465891

RESUMO

Achieving the conversion from surface waves (SWs) to propagating waves has captivated long-standing interest, and various ingenious metasurfaces benefiting from the powerful control capability for electromagnetic waves are able to realize efficient SWs directional radiation. Nevertheless, most existing schemes still suffer from the bottlenecks of single radiation channel, uncontrollable radiation intensity, and immutable radiation pattern, which immensely hinder their practical application in high-integration intelligent devices. Herein, a series of appealing strategies are proposed to achieve the dual-channel SWs directional radiation with customizable radiation intensity and switchable radiation pattern. The dual-channel SWs radiation metadevice based on the phase modulation metasurface is designed to directionally radiate SWs in left-handed circular polarized channel and right-handed circular polarized channel and possesses the broadband frequency scanning characteristic. More strikingly, the intensity-customizable dual-channel SWs radiation metadevice loaded with lumped resistors can control the realized gain of two circular polarized radiation beams, and the pattern-switchable dual-channel SWs radiation metadevice loaded with PIN diodes can dynamically adjust the radiation direction of the radiation beams. Numerous simulations and experiments of the proof-of-concept prototypes with modular design corroborate the theoretical predictions. Our methodology shows unprecedented flexibility in regulating SWs directional radiation and has enormous potential in engineering applications.

17.
ACS Appl Mater Interfaces ; 14(42): 48303-48310, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36250573

RESUMO

Metasurfaces with simultaneously and independently controllable amplitude and phase have provided a higher degree of freedom in manipulating electromagnetic (EM) waves. Compared with phase- or amplitude-only modulation, the capability of simultaneously controlling the phase and amplitude of EM waves can enable holography with a higher resolution. However, this drastically increases the design complexity of holographic metasurfaces, and the design process is usually quite time-consuming. In this paper, we propose an inverse design of meta-atoms that can simultaneously and independently tailor the phase and amplitude of transmitted waves using customized deep ResNet while eliminating the coupling of parameters. To demonstrate the design method, two holographic metasurfaces were designed using the trained network without the need for parameter sweeping, which will significantly enhance design efficiency. Prototypes were fabricated and measured. Both the simulated and measured results show that high-resolution holography is obtained, which sufficiently verifies the reliability of the design method. Our work paves the way for the intelligent design of metasurfaces and can also be applied to the design of other artificial materials or surfaces.

18.
Gene ; 766: 145163, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32980450

RESUMO

BACKGROUND: Cardia adenocarcinoma (CA) is a distinct form of gastric cancer, and the optimal means of treating it remains controversial. At present, the role of the condensation complex gene non-SMC condensin I complex subunit G (NCAPG) in CA is uncertain, and as such the present study was designed to elucidate its importance in this oncogenic context. METHODS: We first used bioinformatics approaches to assess NCAPG expression profiles in CA using public databases. Protein profiling was also used to examine the expression of this protein in CA tumors and adjacent tissues from 20 patients. Then the expression of NCAPG in CA samples was quantified via qRT-PCR and Western blotting. NCAPG knockdown and overexpression in the SGC-7901 and AGS cell lines were subsequently performed, after which the expression of key proteins associated with epithelial-mesenchymal transition (EMT; E-cadherin, vimentin, N-cadherin, Snail, Slug) and the regulation of apoptotic responses (caspase-3, Bax, Bcl-2) was measured. The mechanistic role of NCAPG in CA was additionally studied by analyzing proteins associated with Wnt/ß-catenin signaling including Wnt1, phosphorylated GSK3ß, ß-catenin, and phosphorylated ß- catenin. The impact of NCAPG on the migration, survival, and invasion of CA cells was further examined. RESULTS: CA samples exhibited high NCAPG expression. When this gene was overexpressed in cell lines, it reduced caspase-3, Bax, and E-cadherin levels whereas it elevated Bcl-2, vimentin, N-cadherin, Snail, and Slug levels. NCAPG overexpression also resulted in the enhanced expression of Wnt1, phosphorylated GSK3ß, and total ß-catenin and the reduced expression of phosphorylated ß-catenin. The knockdown of NCAPG, in contrast, yielded the opposite phenotype. At a functional level, the overexpression of NCAPG improved the apoptotic resistance of CA cells while driving them to undergo EMT and to become more invasive and migratory. CONCLUSIONS: NCAPG overexpression can promote EMT and suppress tumor cell apoptosis via the activation of Wnt/ß-catenin signaling.


Assuntos
Adenocarcinoma/genética , Apoptose/genética , Cárdia/patologia , Proteínas de Ciclo Celular/genética , Transição Epitelial-Mesenquimal/genética , Neoplasias Gástricas/genética , Via de Sinalização Wnt/genética , beta Catenina/genética , Adenocarcinoma/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Oncogenes/genética , Neoplasias Gástricas/patologia , Vimentina/genética
19.
Disaster Med Public Health Prep ; : 1-7, 2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34002684

RESUMO

OBJECTIVE: The aim of this study was to present the clinical characteristics and dynamic changes in laboratory parameters of the coronavirus disease 2019 (COVID-19) in Guangzhou, and explore the probable early warning indicators of disease progression. METHOD: We enrolled all the patients diagnosed with COVID-19 in the Guangzhou No. 8 People's Hospital. The patients' demographic and epidemiologic data were collected, including chief complaints, lab results, and imaging examination findings. RESULTS: The characteristics of the patients in Guangzhou are different from those in Wuhan. The patients were younger in age, predominately female, and their condition was not commonly combined with other diseases. A total of 75% of patients suffered fever on admission, followed by cough occurring in 62% patients. Comparing the mild/normal and severe/critical patients, being male, of older age, combined with hypertension, abnormal blood routine test results, raised creatine kinase, glutamic oxaloacetic transaminase, lactate dehydrogenase, C-reactive protein, procalcitonin, D-dimer, fibrinogen, activated partial thromboplastin time, and positive proteinuria were early warning indicators of severe disease. CONCLUSION: The patients outside epidemic areas showed different characteristics from those in Wuhan. The abnormal laboratory parameters were markedly changed 4 weeks after admission, and also were different between the mild and severe patients. More evidence is needed to confirm highly specific and sensitive potential early warning indicators of severe disease.

20.
Int J Clin Exp Pathol ; 13(5): 1176-1184, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32509092

RESUMO

BACKGROUND: Nanog and CD133 are biomarkers of cancer stem cells (CSCs) that regulate cancer progression. The WW domain-containing oxidoreductase (WWOX) is a tumor suppressor protein that can inhibit tumor cell proliferation. The purpose of this study was to investigate the expression and clinical significance of Nanog, CD133, and WWOX in infiltrating breast cancer (IBC). METHODS: Expressions of Nanog, CD133, and WWOX in 204 IBC specimens and their corresponding control specimens were detected by immunohistochemistry. Patients' clinicopathologic and follow-up data were also collected. RESULTS: The rates of positive expression of Nanog and CD133 were significantly higher in IBC specimens than in control specimens, and their expression was positively associated with tumor size, grade, and tumor stages, lymph node metastasis (LNM), and tumor-node-metastasis (TNM) stage. The rate of positive expression of WWOX was significantly lower in IBC specimens than in control specimens, and its expression was inversely associated with tumor size, grade, and tumor stages, LNM, and TNM stage. Patients whose specimens expressed Nanog, CD133, or HER2 had a reduced overall survival (OS) when compared with patients not expressing these proteins. However, patients whose specimens expressed WWOX, ER, or PR had an increased OS when compared with patients who did not show expression. Multivariate analysis demonstrated that expression of Nanog, CD133, WWOX, ER, and HER2, and the TNM stage were independent prognostic factors for IBC patients. CONCLUSIONS: Therefore, Nanog, CD133, and WWOX should be considered as promising prognostic factors and therapeutic targets in IBC.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA