Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Entropy (Basel) ; 24(11)2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36421549

RESUMO

Controlling the motional state of a particle in a multidimensional space is key for fundamental science and quantum technologies. Applying a recently found two-dimensional invariant combined with linear invariants, we propose protocols to drive a particle in two dimensions so that the final harmonic trap is translated and rotated with respect to the initial one. These protocols realize a one-to-one mapping between initial and final eigenstates at some predetermined time and avoid any final excitations.

2.
Entropy (Basel) ; 22(3)2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33286036

RESUMO

We find the noise sensitivities (i.e., the quadratic terms of the energy with respect to the perturbation of the noise) of a particle shuttled by an optical lattice that moves according to a shortcut-to-adiabaticity transport protocol. Noises affecting different optical lattice parameters, trap depth, position, and lattice periodicity, are considered. We find generic expressions of the sensitivities for arbitrary noise spectra but focus on the white-noise limit as a basic reference, and on Ornstein-Uhlenbeck noise to account for the effect of non-zero correlation times.

3.
FEBS Open Bio ; 9(1): 35-42, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30652072

RESUMO

It was recently suggested that growth differentiation factor-15 (GDF-15) is associated with gastric cancer (GC) carcinogenesis. However, the diagnostic potential of GDF-15 for GC remains unclear. To address this issue, we obtained RNA sequencing and microarray data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases, and searched PubMed, Google Scholar and Web of Science for relevant literature. We then used STATA to perform a meta-analysis. In total, reports of 253 GC patients and 112 healthy controls who contributed peripheral blood samples were taken from the four literature sources, while information on 754 GC tumor and 263 gastric normal tissues was drawn from TCGA and seven GEO datasets. The expression level of GDF-15 mRNA was significantly higher in tumor tissues than in normal tissues, with a standard mean difference (SMD) of 0.79% and a 95% confidence interval (95% CI) of 0.63-0.95. Consistently, the GDF-15 protein in blood was significantly increased in GC patients as compared to controls (SMD  = 3.74, 95% CI = 1.81-5.68). In addition, based on information from TCGA and GEO datasets, the expression level of GDF-15 mRNA may be of use for the diagnosis of GC, with a combined sensitivity, specificity and odds ratio of 0.69 (95% CI = 0.58-0.79), 0.90 (95% CI = 0.84-0.93) and 6.32 (95% CI = 4.22-9.49), respectively. The summary receiver operating characteristic curve demonstrated that the area under the curve was 0.90 (95% CI = 0.87-0.93). The results suggest higher levels of GDF-15 may be associated with GC tumorigenesis and may have the potential to be a diagnostic biomarker of GC.


Assuntos
Biomarcadores Tumorais/genética , Bases de Dados Genéticas , Regulação Neoplásica da Expressão Gênica/genética , Fator 15 de Diferenciação de Crescimento/genética , Neoplasias Gástricas/genética , Biomarcadores Tumorais/análise , Perfilação da Expressão Gênica , Fator 15 de Diferenciação de Crescimento/análise , Humanos , RNA Mensageiro/genética , Neoplasias Gástricas/diagnóstico
4.
Sci Rep ; 8(1): 9310, 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29915182

RESUMO

We propose an effective scheme to implement fast and robust population transfer with a Josephson qutrit via shortcut to adiabaticity. Facilitated by the level-transition rule, a Λ-configuration resonant interaction can be realized between microwave drivings and the qutrit with sufficient level anharmonicity, from which we perform the reversible population transfers via invariant-based shortcut. Compared with the detuned drivings, the utilized resonant drivings shorten the transfer times significantly. Further analysis of the dependence of transfer time on Rabi couplings is helpful to experimental investigations. Thanks to the accelerated process, transfer operation is highly insensitive to noise effects. Thus the protocol could provide a promising avenue to experimentally perform fast and robust quantum operations on Josephson artificial atoms.

5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 624-30, 2016 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-27400494

RESUMO

Compared with traditional sampling-based sensing method, absorption spectroscopy technology is well suitable for detonation flow diagnostics, since it can provide with us fast response, nonintrusive, sensitive solution for situ measurements of multiple flow-field parameters. The temperature and concentration test results are the average values along the laser path with traditional absorption spectroscopy technology, while the boundary of detonation flow external field is unknown and it changes all the time during the detonation engine works, traditional absorption spectroscopy technology is no longer suitable for detonation diagnostics. The trend of line strength with temperature varies with different absorption lines. By increasing the number of absorption lines in the test path, more information of the non-uniform flow field can be obtained. In this paper, based on multispectral absorption technology, the reconstructed model of detonation flow external field distribution was established according to the simulation results of space-time conservation element and solution element method, and a diagnostic method of detonation flow external field was given. The model deviation and calculation error of the least squares method adopted were studied by simulation, and the maximum concentration and temperature calculation error was 20.1% and 3.2%, respectively. Four absorption lines of H2O were chosen and detonation flow was scanned at the same time. The detonation external flow testing system was set up for the valveless gas-liquid continuous pulse detonation engine with the diameter of 80 mm. Through scanning H2O absorption lines with a high frequency of 10 kHz, the on-line detection of detonation external flow was realized by direct absorption method combined with time-division multiplexing technology, and the reconstruction of dynamic temperature distribution was realized as well for the first time, both verifying the feasibility of the test method. The test results show that both of the temperature and H2O concentration rose with the arrival of detonation wave. With the increase of the vertical distance between the detonation tube nozzle and the laser path, the time of temperature and concentration coming to the peak delayed, and the temperature variation trend tended to slow down. At 20 cm from detonation tube nozzle, the maximum temperature hit 1 329 K and the maximum H2O concentration of 0.19 occurred at 4 ms after ignition. The research can provide with us the support for expanding the detonation test field with absorption spectroscopy technology, and can also help to promote the detonation mechanism research and to enhance the level of detonation engine control technology.

6.
J Biomater Appl ; 30(2): 133-46, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25766037

RESUMO

The aim of this work was to develop long-term radiopaque microspheres (LRMs) by entrapping lipiodol in biocompatible polyvinyl alcohol with multiple emulsions chemical crosslinking method. The high content of lipiodol (0.366 g/mL) was hardly released from LRMs in vitro and the radiopacity could maintain at least 3 months after subcutaneous injection in mice without weakening. A series of tests was performed to evaluate the feasibility of LRMs for embolization. LRMs were proved to be smooth, spherical, and well dispersed with diameter range of 100-1200 µm. Young's modulus of LRMs was 55.39 ± 9.10 kPa and LRMs could be easily delivered through catheter without aggregating or clogging. No toxicity of LRMs was found to mouse L929 fibroblasts cells and only moderate inflammatory in surrounding tissue of mice was found after subcutaneous injection of LRMs. After LRMs were embolized in renal artery of a rabbit, the distribution and radiopacity of LRMs in vivo were easily detectable by X-ray fluoroscopy and computed tomography (CT) imaging, respectively. More accurate distribution of LRMs in embolized kidney and vessels could be detected by high-revolution visualization of micro-CT ex vivo. In conclusion, the LRMs were proved to be biocompatible and provide long-term radiopacity with good physical and mechanical properties for embolization.


Assuntos
Materiais Biocompatíveis , Embolização Terapêutica , Óleo Etiodado/química , Microesferas , Álcool de Polivinil/química , Animais , Feminino , Fluoroscopia , Camundongos , Coelhos , Tomografia Computadorizada por Raios X
7.
Beijing Da Xue Xue Bao Yi Xue Ban ; 46(5): 733-8, 2014 Oct 18.
Artigo em Chinês | MEDLINE | ID: mdl-25331396

RESUMO

OBJECTIVE: To develop and study the properties of crosslinked polyvinyl alcohol microspheres (PVA-Ms) for embolization. METHODS: The PVA-Ms were produced by emulsion chemical crosslinking method. Fourier transform infrared spectroscopy (FT-IR) was used to investigate the special functional groups of PVA-Ms; the morphology and particle size of PVA-Ms were determined by optical microscope; the ratio of water absorption and the swelling ratio were also investigated; the compressibility was examined by texture analyzer. A new device was designed to measure the pressure of PVA-Ms during their delivery through catheter for embolization. RESULTS: The crosslinking reaction of PVA and formaldehyde was proved by FT-IR. The PVA-Ms were round with smooth surface. The average diameter of lyophilized PVA-Ms was 574.2 µm with a range of 80-1 800 µm and of wet PVA-Ms was 602.2 µm with a range of 100-1 900 µm. The average ratio of water absorption was 175% and the swelling ratio was 48.6%. The PVA-Ms were mechanically stable with appropriate elasticity and delivered through the catheter without any difficulty, and the pressure was higher for larger size of microspheres to be delivered. CONCLUSION: PVA-Ms prepared in this study was supposed to be suitable for clinical embolization according to the physicochemical properties. The study provides a series of methods to evaluate the properties of microspheres systemically for embolization in vitro.


Assuntos
Embolização Terapêutica , Microesferas , Álcool de Polivinil , Elasticidade , Emulsões , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(3): 582-6, 2014 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-25208369

RESUMO

The effect detection of detonation exhaust can provide measurement data for exploring the formation mechanism of detonation, the promotion of detonation efficiency and the reduction of fuel waste. Based on tunable diode laser absorption spectroscopy technique combined with double optical path cross-correlation algorithm, the article raises the diagnosis method to realize the on-line testing of detonation exhaust velocity, temperature and H2O gas concentration. The double optical path testing system is designed and set up for the valveless pulse detonation engine with the diameter of 80 mm. By scanning H2O absorption lines of 1343nm with a high frequency of 50 kHz, the on-line detection of gas-liquid pulse detonation exhaust is realized. The results show that the optical testing system based on tunable diode laser absorption spectroscopy technique can capture the detailed characteristics of pulse detonation exhaust in the transient process of detonation. The duration of single detonation is 85 ms under laboratory conditions, among which supersonic injection time is 5.7 ms and subsonic injection time is 19.3 ms. The valveless pulse detonation engine used can work under frequency of 11 Hz. The velocity of detonation overflowing the detonation tube is 1,172 m x s(-1), the maximum temperature of detonation exhaust near the nozzle is 2 412 K. There is a transitory platform in the velocity curve as well as the temperature curve. H2O gas concentration changes between 0-7% during detonation under experimental conditions. The research can provide measurement data for the detonation process diagnosis and analysis, which is of significance to advance the detonation mechanism research and promote the research of pulse detonation engine control technology.

9.
Beijing Da Xue Xue Bao Yi Xue Ban ; 46(4): 629-34, 2014 Aug 18.
Artigo em Chinês | MEDLINE | ID: mdl-25131483

RESUMO

OBJECTIVE: To prepare doxorubicin-loaded polyvinylalcohol-acrylic acid (PVA-AA) microspheres and evaluate properties of this chemoembolic agent. METHODS: PVA-AA microspheres were synthesized by inverse suspension polymerization method and then verified by infrared spectroscopy. drug loading (DL) and entrapment efficiency (EE%) were measured after doxorubicinwas loaded on PVA-AA microspheres. Their morphology and elasticity were investigated by optical microscope, environmental scanning electron microscope and texture analyzer, respectively. T-cell apparatus was used to evaluate the in vitro release behavior of doxorubicin-loaded microspheres.The external carotid of the rabbit was chosen as an embolization site to evaluate the in vivo embolic property of the microspheres. RESULTS: PVA-AA microspheres, which were transparent spheres,turned into red spheres after doxorubicin loading. DL of the microspheres was (20.56 ± 0.69)g/L and (23.25 ± 0.27) g/L,and EE% was 82.22% ± 2.76% and 93.00% ± 1.06% within 20 min and 6 h, respectively. The in vitro release results showed a significantly delayed release of the drug for 10.32% ± 0.47% after 24 h. The Young's modulus was (178.30 ± 12.33) kPa and (213.29 ± 15.61) kPa for blank microspheres and doxorubicin-loaded microspheres, respectively. Both blank microspheres and doxorubicin-loaded microspheres exhibited good elasticity. In vivo embolization showed that 0.3 mL of microspheres could produce distal embolic efficiency. CONCLUSION: The doxorubicin-loaded microspheres are expected to be a promising new chemoembolic agent.


Assuntos
Doxorrubicina/química , Portadores de Fármacos/química , Microesferas , Acrilatos , Animais , Elasticidade , Embolização Terapêutica , Álcool de Polivinil , Coelhos
10.
Int J Pharm ; 471(1-2): 285-96, 2014 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-24858389

RESUMO

New type of liquid embolic agents based on a liquid crystalline material of glyceryl monooleate (GMO) was developed and evaluated in this study. Ternary phase diagram of GMO, water and ethanol was constructed and three isotropic liquids (ILs, GMO:ethanol:water=49:21:30, 60:20:20 and 72:18:10 (w/w/w)) were selected as potential liquid embolic agents, which could spontaneously form viscous gel cast when contacting with water or physiological fluid. The ILs exhibited excellent microcatheter deliverability due to low viscosity, and were proved to successfully block the saline flow when performed in a device to simulate embolization in vitro. The ILs also showed good cytocompatibility on L929 mouse fibroblast cell line. The embolization of ILs to rabbit kidneys was performed successfully under monitoring of digital subtraction angiography (DSA), and embolic degree was affected by the initial formulation composition and used volume. At 5th week after embolization, DSA and computed tomography (CT) confirmed the renal arteries embolized with IL did not recanalize in follow-up period, and an obvious atrophy of the embolized kidney was observed. Therefore, the GMO-based liquid embolic agents showed feasible and effective to embolize, and potential use in clinical interventional embolization therapy.


Assuntos
Materiais Biocompatíveis/química , Embolização Terapêutica/métodos , Glicerídeos/química , Cristais Líquidos/química , Animais , Materiais Biocompatíveis/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Etanol/química , Fibroblastos/efeitos dos fármacos , Géis , Glicerídeos/toxicidade , Cristais Líquidos/toxicidade , Camundongos , Transição de Fase , Coelhos , Radiografia , Artéria Renal/diagnóstico por imagem , Artéria Renal/efeitos dos fármacos , Viscosidade , Água/química
11.
Int J Pharm ; 452(1-2): 211-9, 2013 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-23707965

RESUMO

Embolic agents, such as microparticles, microspheres or beads used in current embolotherapy are mostly radiolucent, which means the agents are invisible under X-ray imaging during and after the process of embolization, and the fate of these particles cannot be precisely assessed. In this research, a radiopaque embolic agent was developed by encapsulating lipiodol in polyvinyl alcohol. The lipiodol-containing polyvinyl alcohol microcapsules (LPMs) were characterized and evaluated for their morphology, size distribution, lipiodol content, lipiodol release, elasticity, and deliverability through catheter. The radiopacity of LPMs in vials and in living mice was both detected by an X-ray imaging system. The biocompatibility of LPMs was investigated with L929 cells and in mice after subcutaneous injection. Embolization of LPMs to a rabbit kidney was performed under digital subtraction angiography (DSA) and the radiopacity of LPMs was verified by computed tomography (CT).


Assuntos
Meios de Contraste/administração & dosagem , Álcool de Polivinil/administração & dosagem , Angiografia Digital , Animais , Artérias , Materiais Biocompatíveis/administração & dosagem , Materiais Biocompatíveis/química , Cápsulas , Cateterismo , Meios de Contraste/química , Elasticidade , Embolização Terapêutica , Óleo Etiodado/administração & dosagem , Óleo Etiodado/química , Feminino , Rim/metabolismo , Camundongos , Tamanho da Partícula , Álcool de Polivinil/química , Coelhos , Tomografia Computadorizada por Raios X
12.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 21(1): 68-72, 2013 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-23484694

RESUMO

This study was aimed to investigate the expression of plasma miR-223 in pediatric acute lymphoblastic leukemia (ALL) in different treatment time point. A total of 64 pediatric ALL samples were selected from patients treated in Beijing Children's Hospital from May 2005 to January 2012, including 30 samples at new diagnosis (ND), 30 samples at complete remission (CR) and 4 samples at relapse. Without RNA extraction, the miR-223 levels in plasma were directly detected by a reverse-transcription quantitative real-time PCR assay. The results indicated that the expression of plasma miR-223 in pediatric ALL was lower at ND but elevated after CR. The miR-223 expression in plasma of relapse patients didn't show significant difference probably due to a few cases of relapse. The miR-223 levels in plasma had not displayed significant difference between TEL-AML1 positive patients and no fusion gene B lineage ALL patients either at ND or at CR. It is concluded that the plasma miR-223 decreases at ND and increases in CR of children with ALL. miR-223 may act as an anti-oncogene and may be taken as a potential predictive biomarker for evaluating the therapeutic effect of leukemia.


Assuntos
MicroRNAs/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Criança , Pré-Escolar , Feminino , Humanos , Masculino , MicroRNAs/sangue , Plasma/metabolismo
13.
Int J Pharm ; 436(1-2): 527-35, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22820132

RESUMO

A new embolic agent, poly(acrylic acid) microspheres (PMs), was synthesized and the cytocompatibility was proved by mouse L929 fibroblast cells. An analgesic drug, lidocaine, was loaded on the PMs to relief pain caused by embolization. PMs and lidocaine loaded microspheres (LMs) were characterized by investigating infrared spectrum, morphology, particle size, and equilibrium water contents (EWC). A series of tests were employed to evaluate the elasticity of PMs, LMs and Embosphere™, including once compression, twice compression, and stress relaxation test. The pressures of PMs and LMs passing through a catheter were measured on line by our new designed device. Drug release was studied with T-cell apparatus. The properties of PMs and LMs were proved to be suitable for embolization. Both PMs and LMs in this study might be potential embolic agents in the future.


Assuntos
Resinas Acrílicas/química , Anestésicos Locais/química , Portadores de Fármacos/química , Lidocaína/química , Resinas Acrílicas/administração & dosagem , Anestésicos Locais/administração & dosagem , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Força Compressiva , Portadores de Fármacos/administração & dosagem , Elasticidade , Lidocaína/administração & dosagem , Camundongos , Microesferas , Embolização da Artéria Uterina
14.
Opt Lett ; 37(9): 1526-8, 2012 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-22555726

RESUMO

Using Yasumoto and Õishi's energy flux method, a generalized analytical formulation for analyzing the Goos-Hänchen (GH) shift in frustrated total internal reflection is provided, from which the GH shift given by Artman's stationary phase method is shown to equal the GH calculated by Renard's conventional energy flux method plus a self-interference shift. The self-interference shift, originating from the interference between the incident and reflected beams, sheds light on the asymptotic behavior of the GH shift in such optical tunneling process in term of energy flux.

15.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 2): o428, 2012 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-22347041

RESUMO

In the title mol-ecule, C(22)H(26)N(6)O(2), the central tetra-zine ring exhibits a boat conformation, and the two phenyl rings form a dihedral angle of 88.39 (6)°. In the crystal, weak N-H⋯O and C-H⋯O hydrogen bonds link mol-ecules into layers parallel to the ab plane.

16.
Ying Yong Sheng Tai Xue Bao ; 22(3): 614-20, 2011 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-21657015

RESUMO

In order to understand the soil heavy metals characteristics in different type plantations in Harbin City, 0-10 cm and 10-30 cm soil samples were collected from eight mono-cultured plantations (Larix gmelinii, Pinus sylvestris var. mongolica, Pinus tabulaeformis var. mukdensis, Phellodendron amurense, Juglans mandshurica, Fraxinus mandshurica, Betula platyphylla, and Quercus mongolica) and one mixed plantation (P. sylvestris var. mongolica + F. mandshurica + Pinus koraiensis + P. amurense + B. platyphylla) established in the Urban Forestry Demonstration Research Base of Northeast Forestry University in the 1950s to analyze the concentrations of Cu, Zn, Cd, Ni, Pb, and As, and the comprehensive pollution index was used to assess the soil heavy metals pollution in the plantations, based on the background values of black soil in the City. There existed significant differences in the heavy metals concentration in the same soil layers among different type plantations. In the test plantations, the concentrations of soil heavy metals except As and Ni tended to decrease with soil depth. In the same soil layers, Zn had the highest concentration (62.29-126.35 mg x kg(-1)), while Cd had the lowest one (0.06-0.47 mg x kg(-1)). The abundance and accumulation tendency of test heavy metals in the plantations was in the order of Zn>Pb>Cu(Ni)> Ni(Cu)>As>Cd, and Cd>Pb>Zn>Cu>Ni>As, respectively. There existed positive correlations among soil Cu, Zn, Pb, and Cd concentrations in the plantations except F. mandshurica, and the concentrations of these four heavy metals in the plantations except F. mandshurica and Q. mongolica were positively correlated with soil organic matter, N, P, and K. The concentrations of soil Cd, Pb, Zn, and Cu were higher than the background values, suggesting the anthropogenic inputs; while those of Ni and As were similar to or lower than the background values, suggesting the origin from soil materials. The soil comprehensive pollution index of the plantations was decreased in the order of F. mandshurica > P. amurense > mixed plantation > J. mandshurica > P. sylvestris var. mongolica > P. tabulaeformis var. mukdensis > L. gmelinii >B. platyphylla > Q. mongolica.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Árvores/classificação , Árvores/crescimento & desenvolvimento , China , Cidades , Monitoramento Ambiental , Juglans/crescimento & desenvolvimento , Larix/crescimento & desenvolvimento , Pinus/crescimento & desenvolvimento , Solo/análise
17.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 1): m243-4, 2007 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-21200585

RESUMO

In the title compound, [Cu(C(10)H(10)NO(3))(C(5)H(8)N(2))(2)]·2H(2)O, the Cu(II) atom is coordinated by three N atoms and two O atoms in a distorted square-pyramidal geometry. The crystal packing is stabilized by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...