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1.
Pediatr Blood Cancer ; : e30382, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37283279

RESUMO

OBJECTIVE: To analyze the prognostic factors of sepsis in children with acute leukemia admitted to the pediatric intensive care unit (PICU) and to compare the efficacy of different scoring systems for predicting the outcome of children. METHODS: Patients with an acute leukemia diagnosis admitted to a tertiary care university hospital PICU due to sepsis during chemotherapy between May 2015 and August 2022 were retrospectively analyzed through an electronic medical record system. RESULTS: During this period, 693 children with acute leukemia initially diagnosed were admitted to the center, and 155 (22.3%) of them were transferred to PICU due to deterioration of the disease during treatment. Total 109 (70.3%) patients were transferred to PICU due to sepsis. Here, 17 patients was excluded (prior treatment from another hospital; referring from other hospitals; discontinued treatment; incomplete medical record). Of the 92 patients studied, the mortality rate was 35.9%. Multivariate analysis revealed that remission status, lactate level, invasive mechanical ventilation (IMV), and inotropic support within 48 hours after PICU transfer were independent risk factors for PICU mortality. The pediatric sequential organ failure assessment (PSOFA) score had the greatest predictive validity for hospital mortality (area under the receiver operating characteristic curve [AUROC]: 0.83, 95% confidence intervals [CI]: 0.74-0.92), followed by the pediatric early warning score (PEWS) (0.82, 0.73-0.91) and pediatric critical illness score (PCIS) (0.79, 0.69-0.88). CONCLUSION: The mortality rate among children with acute leukemia complicated with sepsis is high after being transferred to the PICU. Various scoring systems can be used to monitor the clinical status of patients, identify sepsis early, detect critical illness, and determine the optimal time for transfer to the PICU for supportive treatment, thereby improving the prognosis of these patients.

2.
J Opt Soc Am A Opt Image Sci Vis ; 40(9): 1706-1713, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37707007

RESUMO

In this paper, we generate a type of double helico-conical beam (HCB) by binarizing the modified helico-conical phase (MHCP). The diffraction patterns of the double HCBs were analyzed theoretically and experimentally. The relative position of the double HCBs can be adjusted arbitrarily by introducing a blazed grating only. In addition, the superposition of multiple binary MHCPs can be used to generate multi-helix beams. Accordingly, the diffraction patterns of the multi-helix beams were also analyzed theoretically and experimentally. The results demonstrated that the number and relative position of multi-helix beams can be adjusted by the number of superimposed MHCP profiles and the azimuth factor θ j, respectively. This kind of arrayed HCB will be potentially applied in the fields of optical manipulation and multiplexed holography.

3.
J Opt Soc Am A Opt Image Sci Vis ; 40(10): 1873-1881, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37855543

RESUMO

The self-healing properties of symmetrical power-exponent-phase vortices (SPEPVs) are analyzed in this paper. By placing an obstacle in the optical path of SPEPVs, we simulated the propagation of the obstructed SPEPVs and verified the self-healing of the beam theoretically. We also explored the influence of external factors (e.g., obstacle size and position) and internal parameters (topological charge l and power exponent n) on the self-healing effect of obstructed SPEPVs. Furthermore, the energy flow density, similarity coefficient, effective self-healing distance, and diffraction efficiency of the obstructed SPEPVs were also discussed. The results demonstrated that the transverse energy flows around the obstructed region of SPEPVs will recover with the propagation distance increased, and the effective self-healing distance gradually increases linearly with the obstacle size r x increased. The self-healing characteristic gives the petal-like SPEPVs the ability to trap microparticles three-dimensionally.

4.
Opt Express ; 30(6): 9924-9933, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35299405

RESUMO

We investigate the dynamic evolution and self-healing properties of the bored helico-conical beams with different filter parameter S in this paper. The relative error coefficient, D, is utilized to judge the self-healing effect of the bored helico-conical beam. The result demonstrates that the self-healing effect of the bored beams will be perfect when D approaches to 0. We also discuss the influence of the filter parameter S on the effective self-healing distance theoretically and experimentally. The result demonstrates that the effective self-healing distance decreases exponentially with the increasing filter parameter S. Moreover, the corresponding transverse energy flows of the bored beams are analyzed. The experimental results of the dynamic evolution for the bored helico-conical beams agree with the simulation ones well.

5.
Opt Express ; 30(4): 5465-5472, 2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35209508

RESUMO

We introduce a class of self-rotating beams whose intensity profile tends to self-rotate and self-bend in the free space propagation. The feature of the self-rotating beams is acceleration in the three-dimensional (3D) space. The acceleration dynamics of the self-rotating beams is controllable. Furthermore, multiple self-rotating beams can be generated by a combined diffractive optical element (DOE) simultaneously. Such a beam can be viewed as evolution of a vortex beam by changing the exponential constant of phase. We have generated this beam successfully in the experiment and observed the expected phenomenon, which is basically consistent with the result of the numerical simulation. Our results may provide new insight into the self-rotating beam and extend potential applications in optical imaging.

6.
Acta Pharmacol Sin ; 43(8): 2067-2080, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34937916

RESUMO

Enhancer of zeste homolog 2 (EZH2), a component of polycomb repressive complex 2 (PRC2), is a histone lysine methyltransferase mediating trimethylation of histone H3 at lysine 27 (H3K27me3), which is a repressive marker at the transcriptional level. EZH2 sustains normal renal function and its overexpression has bad properties. Inhibition of EZH2 overexpression exerts protective effect against acute kidney injury (AKI). A small-molecule compound zld1039 has been developed as an efficient and selective EZH2 inhibitor. In this study, we evaluated the efficacy of zld1039 in the treatment of cisplatin-induced AKI in mice. Before injection of cisplatin (20 mg/kg, i.p.), mice were administered zld1039 (100, 200 mg/kg, i.g.) once, then in the following 3 days. We found that cisplatin-treated mice displayed serious AKI symptoms, evidenced by kidney dysfunction and kidney histological injury, accompanied by EZH2 upregulation in the nucleus of renal tubular epithelial cells. Administration of zld1039 dose-dependently alleviated renal dysfunction as well as the histological injury, inflammation and cell apoptosis in cisplatin-treated mice. We revealed that zld1039 administration exerted an anti-inflammatory effect in kidney of cisplatin-treated mice via H3K27me3 inhibition, raf kinase inhibitor protein (RKIP) upregulation and NF-κB p65 repression. In the cisplatin-treated mouse renal tubular epithelial (TCMK-1) cells, silencing of RKIP with siRNA did not abolish the anti-inflammatory effect of EZH2 inhibition, suggesting that RKIP was partially involved in the anti-inflammatory effect of zld1039. Collectively, EZH2 inhibition alleviates inflammation in cisplatin-induced mouse AKI via upregulating RKIP and blocking NF-κB p65 signaling in cisplatin-induced AKI. The potent and selective EZH2 inhibitor zld1039 has the potential as a promising agent for the treatment of AKI.


Assuntos
Injúria Renal Aguda , Proteína Potenciadora do Homólogo 2 de Zeste , Inibidores Enzimáticos , Proteína de Ligação a Fosfatidiletanolamina , Fator de Transcrição RelA , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Benzamidas/farmacologia , Cisplatino/efeitos adversos , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Histonas/metabolismo , Inflamação , Camundongos , NF-kappa B/metabolismo , Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Quinolonas/farmacologia , Fator de Transcrição RelA/metabolismo
7.
Pediatr Crit Care Med ; 22(12): e605-e612, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33965990

RESUMO

OBJECTIVES: This study was designed to evaluate practice changes and outcomes over a 10-year period in a large single-center PICU cohort that received continuous renal-replacement therapy. DESIGN: Retrospective study design. SETTING: A multidisciplinary tertiary PICU of a university-affiliated hospital in Guangzhou, China. PATIENTS: All critically ill children who were admitted to our PICU from January 2010 to December 2019 and received continuous renal-replacement therapy were included in this study. MEASUREMENTS AND MAIN RESULTS: A total of 289 patients were included in the study. Of the two study periods, 2010-2014 and 2015-2019, the proportion of continuous renal-replacement therapy initiation time greater than 24 hours was significantly reduced ([73/223] 32.73% vs. [40/66] 60.60%, p < 0.001), the percentage of fluid overload at continuous renal-replacement therapy initiation was lower (3.8% [1.6-7.2%] vs. 12.1% [6.6-23.3%], p < 0.001), the percentage of regional citrate anticoagulation protocol was increased ([223/223] 100% vs. [15/66] 22.7%, p < 0.001), and the ICU survival rate was significantly improved ([24/66] 36.4% vs. [131/223] 58.7%, p = 0.001) in the latter period compared with the former. In addition, subgroup analysis found that survival were higher in patients with continuous renal-replacement therapy initiation time less than 24 hours, regional citrate anticoagulation protocol, and fluid overload less than 10%. CONCLUSIONS: The survival rate of patients received continuous renal-replacement therapy treatment in our center has improved over past 10 years, and some changes have taken place during these periods. Among them, early initiation of continuous renal-replacement therapy, lower fluid overload, and regional citrate anticoagulation method seems to be related to the improvement of outcome. Ongoing evaluation of the practice changes and quality improvement of continuous renal-replacement therapy for critically ill pediatric patients still need attention.


Assuntos
Injúria Renal Aguda , Terapia de Substituição Renal Contínua , Desequilíbrio Hidroeletrolítico , Injúria Renal Aguda/terapia , Criança , Ácido Cítrico , Estado Terminal/terapia , Humanos , Terapia de Substituição Renal/métodos , Estudos Retrospectivos
8.
Opt Express ; 28(25): 37827-37843, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33379610

RESUMO

A modified single-focus fractal zone plate (MSFFZP) is proposed to generate a single main focus with many subsidiary foci or two equal-intensity main foci with many subsidiary foci. Widths of high-transmission zones, which have influence on the number of the high-order diffraction foci, such as the second-order focus and the fourth-order focus, can adjust first-order fractal focal intensities, but have no influence on first-order focal positions. Moreover, the MSFFZPs have the first-order foci or the first and second order foci only along the optic axis. It is proved numerically and experimentally that the MSFFZP can generate one or two colourful images with the low chromatic aberrations at the focal planes, and the MSFFZP beam has the self-reconstruction property. In addition, the MSFFZP produces a series of foci at the different focal planes along the optic axis in the simulations and experiments. The method of constructing the MSFFZP is illustrated. The proposed zone plate can be used to produce the multiple clear images, trap particles at the multiple planes simultaneously, and generate the images with the low chromatic aberration.

9.
Opt Express ; 28(18): 27181-27195, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32906974

RESUMO

Generalized composite aperiodic zone plates (GCAZPs) are proposed to generate clearer images at focal planes. The images can be produced by a target object at infinity based on a collimator. The proposed zone plate consists of the proposed radial zone plate (RZP), whose original radius is not zero, and the common aperiodic zone plate, which has the coincident first-order diffraction area and the same axial first-order diffraction intensity distribution. The GCAZPs are applicable for the other aperiodic zone plates. Moreover, the modulation transfer function curve of the GCAZP is basically above that of the corresponding common aperiodic zone plate. Compared with the common aperiodic zone plates, the GCAZPs have the foci with higher intensity and the images with higher contrast at the same focal planes. In addition, a GCAZP with an arbitrary size can be designed. The construction method of the GCAZP is illustrated in details. Furthermore, it has been also proved numerically and experimentally that the GCAZPs are used to generate the clearer images than the corresponding common aperiodic zone plates. The proposed zone plates are applicable to generate clear images and trap particles stably at multiple planes simultaneously.

10.
J Opt Soc Am A Opt Image Sci Vis ; 37(6): 1067-1074, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32543610

RESUMO

A modified precious mean zone plate (MPMZP) is proposed to generate twin equal-intensity foci with the same resolution related to the precious mean. The MPMZP with a bigger copy number C can generate two equal-intensity foci with approximately the same resolution. The energy efficiencies of twin foci generated by the MPMZP are approximately the same. Moreover, the MPMZP with a helical phase can generate twin vortices with the same diameter. In addition, it is proven numerically that the MPMZP beam and the spiral-phase MPMZP beam have the self-reconstruction property. The construction method of the MPMZP is illustrated in detail. Moreover, it is proven in the simulations and experiments that twin equal-intensity foci generated by the MPMZP have the same resolution, and the spiral-phase MPMZP can produce twin vortices with the same diameter. The proposed zone plate can be used for optical lithography in two planes at the same extent, and applied to rotate different particles in two planes at the same speed and generate two of the same clear images at two planes related to the precious mean.

11.
Opt Express ; 25(15): 18346-18354, 2017 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-28789321

RESUMO

This paper describes the tri-phase all-optical switching and broadband nonlinear optical response in Bi2Se3 nanosheets. Using Bi2Se3 nanosheets dispersion solution as the sample, the spatial phase of controlled light can be modulated as three phases (unchanging, focusing, diffraction) by changing the incident intensity of controlling light. The mechanism is conjectured that the controlling light changes the phase distribution of overlapping region and then modulates the phase distribution of the controlled light. Based on Gerchberg-Saxton algorithm, the phase distribution of the controlling light and controlled light is retrieved from the transmitted patterns. In dynamic spatial self-phase modulation (SSPM) experiment, the three processes including self-focusing, self-diffraction ring formation, and self-diffraction ring deformation can also be observed. In addition, the SSPM of controlling light is measured at the typical wavelengths from 350 nm to 1160 nm, which demonstrates that this all-optical switching is available in broadband. These results provide the great potential of Bi2Se3 as an all-optical switching for various optoelectronic applications.

12.
Int J Neurosci ; 127(1): 1-9, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26710878

RESUMO

PURPOSE: This work aimed to assess whether elevated levels of cerebrospinal fluid (CSF) S100B are associated with brain injury and unfavorable outcomes at discharge in children with central nervous system (CNS) infections. METHODS: CSF S100B and associated clinical parameters were retrospectively analyzed in 83 children with CNS infections and 88 children without neurological pathology served as controls. Children with CNS infections were divided into an infectious encephalitis group and an infectious meningitis group based on whether cerebral parenchyma was involved, and CSF S100B levels in different age subgroups between the two groups were compared. The predictive value of CSF S100B in children with infectious encephalitis was evaluated by multivariate logistic regression analysis, and the discriminative power was investigated by receiver operating characteristic (ROC) analysis. RESULTS: CSF S100B levels in the infectious encephalitis group were significantly higher than the infectious meningitis and the control group at each age range. CSF S100B ≥ 0.96 µg/L had 62.9% sensitivity and 76.2% specificity for diagnosing cerebral parenchyma injury in children with CNS infections. Increased CSF S100B levels were proven to be an independent predictor of unfavorable outcomes in children with infectious encephalitis and the optimal cut-off value (1.77 µg/L of CSF S100B) for predicting unfavorable outcomes in children with infectious encephalitis showed 61.1% sensitivity and 96.2% specificity. CONCLUSIONS: This study has demonstrated that elevated levels of CSF S100B are associated with brain injury and could be used as an independent predictor of clinically unfavorable outcomes at discharge in children with CNS infections.


Assuntos
Lesões Encefálicas/líquido cefalorraquidiano , Infecções do Sistema Nervoso Central/líquido cefalorraquidiano , Encefalite Infecciosa/líquido cefalorraquidiano , Avaliação de Resultados em Cuidados de Saúde , Subunidade beta da Proteína Ligante de Cálcio S100/líquido cefalorraquidiano , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Estudos Retrospectivos , Sensibilidade e Especificidade
13.
Opt Express ; 24(12): 12740-7, 2016 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-27410293

RESUMO

We present a new family of diffractive lenses, composite Thue-Morse zone plates (CTMZPs), formed by multiple orders of Thue-Morse zone plates (TMZPs). The typical structure of a CTMZP is a composite of two concentric TMZPs. The focusing properties of the CTMZPs with different parameters have been investigated both theoretically and experimentally. Compared with the TMZPs, the CTMZPs have higher performance in axial intensity and imaging resolution. The CTMZP beams are also found to possess the self-reconstruction property, and would be useful for three-dimensional optical tweezers, laser machining, and optical imaging.

14.
BMC Infect Dis ; 16: 128, 2016 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-26983856

RESUMO

BACKGROUND: A series of complications caused by enteroviruses, including meningitis, encephalitis, acute flaccid paralysis, acute cardiopulmonary failure, respiratory infection, and myocardial injury have been reported in hand, foot and mouth disease/herpangina (HFMD/HA). However, the complication of diarrhoea caused by enteroviruses has been neglected, and a summary of its clinical features and impact on HFMD/HA is unavailable. METHODS: We included inpatients with HFMD/HA admitted to the Paediatric Department of Zhujiang Hospital during 2009-2012. We summarised and compared clinical data for cases with and without diarrhoea, and determined enterovirus serotypes by reverse transcriptase polymerase chain reaction and genotyping based on a partial-length fragment of viral protein 1 or the 5'-untranslated region. RESULTS: There were 804 inpatients with HFMD/HA and 28 (3.5%) presented with diarrhoea. Gastrointestinal symptoms were mild in most cases of diarrhoea (82.1%), with high prevalence of no dehydration (82.1%), short duration of diarrhoea (78.6%) and watery stools (75.0%). The prevalence of multi-organ dysfunction syndrome (10.7 vs 0.40%) (p = 0.001), hepatic injury (14.3 vs 3.4%) (p = 0.019), myocardial injury (21.4 vs 6.1%) (p = 0.002) and convulsion (21.4 vs 7.2%) (p = 0.016) was significantly higher in the diarrhoea than no diarrhoea group. There was no significant difference between the two groups regarding prevalence of death, altered consciousness, paralysis, central nervous system involvement, or acute respiratory infection. CONCLUSIONS: Most patients with diarrhoea caused by enteroviruses circulating in Guangdong Province in 2009-2012 had mild or moderate gastrointestinal symptoms. Although enterovirus-related diarrhoea caused additional multi-organ dysfunction syndrome, hepatic injury and myocardial injury in children with HFMD/HA, timely intervention efficiently reduced disease severity and improved outcome.


Assuntos
Infecções por Enterovirus/epidemiologia , Enterovirus/isolamento & purificação , Doença de Mão, Pé e Boca/epidemiologia , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Diarreia/epidemiologia , Diarreia/virologia , Infecções por Enterovirus/virologia , Feminino , Genótipo , Doença de Mão, Pé e Boca/virologia , Herpangina/epidemiologia , Herpangina/virologia , Humanos , Masculino , Prevalência
15.
BMC Infect Dis ; 16: 399, 2016 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-27506778

RESUMO

BACKGROUND: Enterovirus (EV)-related hand, foot, and mouth disease/herpangina (HFMD/HA) has been prevalent in Guangdong Province, China, since 2010. METHODS: Clinical data for EV-related HFMD/HA inpatients admitted to the Department of Paediatrics of Zhujiang Hospital from 2010 to 2013 were retrospectively reviewed. The corresponding EV serotypes were also determined by reverse transcription-polymerase chain reaction or BLAST analysis of the sequenced partial lengths of the viral protein1/5'-untranslated region. RESULTS: A total of 867 eligible inpatients admitted during 2010-2013 were included in the study. Of these, the serotype of the responsible EV was successfully identified in 824 cases. The incidence of enterovirus 71 (EV71) infection amongst pediatric HFMD/HA inpatients decreased dramatically from 55.5 % in 2010 to 8.1 % in 2013, with a similar decrease recorded for coxsackievirus A16 (CVA16). However, the incidence of non-EV71/CVA16 infection increased from 30.0 % in 2010 to 83.8 % in 2013. We noted that the types of infection caused by different EV serotypes varied: EV71 was responsible for 100 % of the paralysis cases (26/26), 84.6 % of the deaths (11/13), and 84.1 % of cases with severe central nervous system involvement (SCNSI) (74/88); echovirus contributed to 16.4 % of the deaths (2/13) and 4.4 % of the SCNSI cases; and coxsackievirus accounted for only 2.2 % of the SCNSI cases (2/90). The clinical features of HFMD/HA cases varied greatly during the time period examined, with drastic changes in the hospitalization rates (45.1, 63.7, 36.4, and 19.1 % for 2010, 2011, 2012, and 21013, respectively), mortality rates (2.3, 0.9, 2.5, and 0.0 %, respectively), paralysis (5.1, 1.2, 5.4, and 0.0 %, respectively), SCNSI (16.8, 7.1, 12.7, and 2.2 %, respectively), and acute respiratory infection (21.1, 22.0, 45.9, and 59.0 %, respectively). CONCLUSIONS: The incidences of infection caused by different EV serotypes, along with the clinical features of HFMD/HA cases, changed drastically in Guangdong Province, China, from 2010 to 2013, with the biggest changes observed in 2013. The changed constituent ratios of the different EV serotypes might therefore be responsible for the differences in the observed clinical features of HFMD/HA during this period.


Assuntos
Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/etiologia , Enterovirus/patogenicidade , Criança , Pré-Escolar , China/epidemiologia , Enterovirus Humano B/patogenicidade , Infecções por Enterovirus/virologia , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/etiologia , Doença de Mão, Pé e Boca/virologia , Herpangina/epidemiologia , Herpangina/etiologia , Herpangina/virologia , Hospitalização/estatística & dados numéricos , Humanos , Estudos Retrospectivos , Sorogrupo
16.
Opt Express ; 23(2): 1052-62, 2015 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-25835865

RESUMO

We present a beam shaping technique in controlling the complex amplitude of an optical beam. The constraint on the amplitude of the output beam in the Gerchberg-Saxton algorithm is replaced with constraints both on the amplitude and phase of the output beam in the proposed method. The total areas of the constrained regions and free regions on the complex amplitude of the output beam in the proposed method are maintained. An output beam with arbitrary complex amplitude can be realized with the proposed method. The computing result from the proposed method is a phase-only distribution, which can be fabricated as diffractive optical element for higher diffraction efficiency. Both simulations and experiments are present and the effectiveness of the proposed method is verified.

17.
Opt Express ; 23(5): 5875-87, 2015 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-25836814

RESUMO

We observe dynamic self-diffraction in MoS(2) supernatant solutions with laser for the first time, and conduct dynamic data simulation and analysis. Observation results indicate that self-diffraction can be divided in three stages: in the first stage, laser changes from Gauss beam to symmetric diffraction rings because of the force from laser. In the second stage, diffraction rings become asymmetric vertically because of gravity. In the third stage, diffraction rings become asymmetric horizontally, as a result of fine structure of laser. We obtain the dynamic distribution of MoS(2) nanoflake in solution under the effect of laser by dynamic diffraction image simulation.

18.
Nanotechnology ; 26(22): 225601, 2015 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-25961155

RESUMO

Copper phthalocyanine (CuPc) nanostructure crystals, including nanoflower, nanoribbon, and nanowire, were controllably fabricated by temperature gradient physical vapor deposition (TG-PVD) through controlling the growth parameters. In a controllable growth system with carrier gas N2, nanoflower, nanoribbon, and nanowire crystals were formed in a high-temperature zone, medium-temperature zone, and low-temperature zone, respectively. They were proved to be ß-phase, coexist of α-phase and ß-phase, and α-phase respectively based on x-ray diffraction results. Furthermore, ultralong CuPc nanowires up to several millimeters could be fabricated by TG-PVD without carrier gas, and they were well-aligned to form large-area CuPc nanowire crystal arrays by the Langmuir-Blodgett method. The nanostructure crystals showed unusual optical absorption spectra from the ultraviolet-visible to near-infrared range, which was explained by the diffraction and scattering caused by the wavelength-sized nanostructures. These CuPc nanostructure crystals show potential applications in organic electronic and optoelectronic devices.


Assuntos
Indóis/síntese química , Nanopartículas/química , Compostos Organometálicos/síntese química , Teste de Materiais , Nanopartículas/ultraestrutura , Nanotecnologia/métodos , Temperatura
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(4): 881-4, 2015 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-26197567

RESUMO

The methods that can rapidly and precisely measure concentrations of various gases have extensive applications in the fields such as air quality analysis, environmental pollution detection, and so on. The gas detection method based on the tunable laser absorption spectroscopy is considered a promising technique. For the infrared spectrum detection techniques, the line shape function of an absorption spectrum of a gas is an important parameter in qualitative and quantitative analysis of a gas. Specifically, how to obtain the line shape function of an absorption spectrum of a gas quickly and accurately is a key problem in the gas detection fields. In this paper we analyzed several existing line shape functions and proposed a method to calculate precisely the line shape function of a gas, and investigated the relation between the gas concentration and the peak value of a line shape function. Then we experimentally measured the absorption spectra of an acetylene gas in the wavelength range of 1,515-1,545 nm with a tunable laser source and a built-in spectrometer. With Lambert-Beer law we calculated the peak values of the line shape function of the gas at the given frequencies, and obtained a fitting curve for the line shape function in the whole waveband by using a computer program. Comparing the measured results with the calculated results of the Voigt function, we found that there was a deviation-between the experimental results and the calculated results. And we found that the measured concentration of the acetylene gas by using the fitting curve of the line shape function was more accurate and compatible with the actual situation. Hence, the empirical formula for the line shape function obtained from the experimental results would be more suitable for the concentration measurement of a gas. As the fitting curve for the line shape function of the acetylene gas has been deduced from the experiment, the corresponding peak values of the spectral lines can be immediately calculated out from the curve and used for the measurements of different concentrations of acetylene gases. Therefore, the calculation for the line shape function values is greatly simplified. The obtained data of the line shape function of the acetylene gas can be used for remote sensing of the gas, and the proposed method can also be applied for the measurements of line shape functions of other gases.

20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(12): 3490-4, 2015 Dec.
Artigo em Zh | MEDLINE | ID: mdl-26964236

RESUMO

The absorptance spectrum of a gas is the basis for the qualitative and quantitative analysis of the gas by the law of the Lambert-Beer. The integral value of the absorptance spectrum is an important parameter to describe the characteristics of the gas absorption. Based on the measured absorptance spectrum of a gas, we collected the required data from the database of HIT-RAN, and chose one of the spectral lines and calculated the integral value of the absorptance spectrum in the frequency domain, and then substituted the integral value into Lambert-Beer's law to obtain the concentration of the detected gas. By calculating the integral value of the absorptance spectrum we can avoid the more complicated calculation of the spectral line function and a series of standard gases for calibration, so the gas concentration measurement will be simpler and faster. We studied the changing trends of the integral values of the absorptance spectrums versus temperature. Since temperature variation would cause the corresponding variation in pressure, we studied the changing trends of the integral values of the absorptance spectrums versus both the pressure not changed with temperature and changed with the temperature variation. Based on the two cases, we found that the integral values of the absorptance spectrums both would firstly increase, then decrease, and finally stabilize with temperature increasing, but the ranges of specific changing trend were different in the two cases. In the experiments, we found that the relative errors of the integrated values of the absorptance spectrum were much higher than 1% and still increased with temperature when we only considered the change of temperature and completely ignored the pressure affected by the temperature variation, and the relative errors of the integrated values of the absorptance spectrum were almost constant at about only 1% when we considered that the pressure were affected by the temperature variation. As the integral value of the absorptance spectrum varied with temperature and the calculating error for the integral value fluctuates with ranges of temperature, in the gas measurement when we usd integral values of the absoptance spectrum, we should select a suitable temperature variation and obtain a more accurate measurement result.

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