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Zhang Z.,Beijing Normal University | Chen X.,Beijing Normal University | Yu P.,Beijing Normal University | Zhang Q.,Jining Medical University | And 17 more authors.
Neuropsychopharmacology | Year: 2015

Nitric oxide (NO), a gaseous neurotransmitter, has been implicated in the pathogenesis of schizophrenia. Accordingly, several polymorphisms of the gene that codes for the main NO-producing enzyme, the nitric oxide synthase 1 (NOS1), have been found to convey a risk for schizophrenia. This study examined the role of NOS1 gene polymorphisms in cognitive functions and related neural mechanism. First, with a sample of 580 schizophrenia patients and 720 healthy controls, we found that rs3782206 genotype had main effects on the 1-back task (P=0.005), the 2-back task (P=0.049), the AY condition of the dot-pattern expectancy (DPX) task (P=0.001), and the conflict effect of the attention network (ANT) test (P<0.001 for RT differences and P=0.002 for RT ratio) and interaction effects with diagnosis on the BX condition of the DPX (P=0.009), the AY condition of the DPX (P<0.001), and the Stroop conflict effect (P=0.003 for RT differences and P=0.038 for RT ratio). Simple effect analyses further showed that the schizophrenia risk allele (T) of rs3782206 was associated with poorer performance in five measures for the patients (1-back, P=0.025; BX, P=0.017; AY, P<0.001; ANT conflict effect (RT differences), P=0.005; Stroop conflict effect (RT differences), P=0.019) and three measures for the controls (for the 2-back task, P=0.042; for the ANT conlict effect (RT differences), P=0.013; for the ANT conflict effect (RT ratios), P=0.028). Then, with a separate sample of 78 healthy controls, we examined the association between rs3782206 and brain activation patterns during the N-back task and the Stroop task. Whole brain analyses found that the risk allele carriers showed reduced activation at the right inferior frontal gyrus (IFG) during both tasks. Finally, we examined functional connectivity seeded from the right IFG to the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex under three conditions (the N-back task, the Stroop task, and the resting state). Results showed reduced connectivity with the DLPFC for the risk allele carriers mainly in the Stroop task and the resting state. Taken together, results of this study strongly suggested a link between NOS1 gene polymorphism at rs3782206 and cognitive functions and their neural underpinnings at the IFG. These results have important implications for our understanding of the neural mechanism underlying the association between NOS1 gene polymorphism and schizophrenia. © 2015 American College of Neuropsychopharmacology. All rights reserved.


Huang B.,Tianjin University | Huang B.,Key Laboratory of Opto electronics Information Technology | Liu T.,Tianjin University | Liu T.,Key Laboratory of Opto electronics Information Technology | And 4 more authors.
Optics Express | Year: 2015

In polarimetric imaging, the uneven illumination could cause the significant spatial intensity fluctuations in the scene, and thus hampers the target detection. In this paper, we propose a method of illumination compensation and contrast optimization for Stokes polarimetric imaging, which allows significantly increasing the performance of target detection under uneven illumination. We show with numerical simulation and realworld experiment that, based on the intensity information contained in the polarization information, the contrast can be effectively enhanced by proper approach, which is of particular importance in practical applications with spatial illumination fluctuations, such as remote sensing. © 2015 Optical Society of America.


Li X.,Tianjin University | Liu T.,Tianjin University | Liu T.,Key Laboratory of Opto Electronics Information Technology | Huang B.,Tianjin University | And 4 more authors.
Optics Express | Year: 2015

We consider the typical Stokes polarimetry system, which performs four intensity measurements to estimate a Stokes vector. We show that if the total integration time of intensity measurements is fixed, the variance of the Stokes vector estimator depends on the distribution of the integration time at four intensity measurements. Therefore, by optimizing the distribution of integration time, the variance of the Stokes vector estimator can be decreased. In this paper, we obtain the closed-form solution of the optimal distribution of integration time by employing Lagrange multiplier method. According to the theoretical analysis and real-world experiment, it is shown that the total variance of the Stokes vector estimator can be significantly decreased about 40% in the case discussed in this paper. The method proposed in this paper can effectively decrease the measurement variance and thus statistically improves the measurement accuracy of the polarimetric system. © 2015 Optical Society of America.


Hu H.,Tianjin University | Hu H.,Key Laboratory of Opto electronics Information Technology | Liu T.,Tianjin University | Liu T.,Key Laboratory of Opto electronics Information Technology | Zhai H.,Nankai University
Optics Express | Year: 2015

The dynamic process of material ejection and shock wave evolution during one single femtosecond laser pulse ablation of aluminum target in water and air is experimentally investigated by employing pumpprobe technique. Shadowgraphs and digital holograms with high temporal resolution are recorded, which intuitively reveal the characteristics of femtosecond laser ablation in the water-confined environment. The experimental result indicates that the liquid significantly restrict the diffusion of the ejected material, and it has a considerable effect on the attenuation of the shock wave. In addition, the expansion Mach wave generated by the ultrasonic expansion of the shock wave is observed. © 2015 Optical Society of America.


Cao X.-L.,Institute of Laser and Opto electronics | Yao J.-Q.,Institute of Laser and Opto electronics | Zhong K.,Institute of Laser and Opto electronics | Xu D-G.,Institute of Laser and Opto electronics | Xu D-G.,Key Laboratory of Opto electronics Information Technology
Optical Engineering | Year: 2013

Abstract. The intersubband absorptions between the conduction ground state and excited states in Al0.5Ga0.5As/GaAs/Al0.2Ga0.8As multiple asymmetric quantum well (AQW) have been investigated based on optical difference frequency in the 9 to 11 μm region. Under an intense resonant excitation from a dual-wavelength CO2 laser, the saturation intensity of intersubband absorption for pump waves is estimated to be 0.3 MW/cm2. As the well width variation, the position of absorption peak for pump waves and the absorption of terahertz (THz) wave by DFG show concomitant changes. For an AQW of 7 nm deep well-width and 27 nm total well-width, the maximum of absorption for the THz wave is 6.01×105 m-1 when the two pump wavelengths are 9.69 and 10.64 μm, respectively. These manipulative transitions in AQW can be applied to tunable optical semiconductor devices and implemented in THz wave devices to achieve additional functionalities. © 2013 Society of Photo-Optical Instrumentation Engineers (SPIE).


Zhong K.,Tianjin University | Zhong K.,Key Laboratory of Opto electronics Information Technology | Sun C.,Tianjin University | Sun C.,Key Laboratory of Opto electronics Information Technology | And 12 more authors.
IEEE Journal of Quantum Electronics | Year: 2013

Research on an efficient continuous-wave Nd:GYSGG laser at 1053 nm with excellent stability is demonstrated. The maximum output power is 4.17 W, corresponding to the conversion efficiency of 33.9% and the slope efficiency of 42.92%. Using a Cr:YAG absorber, pulsed dual-wavelength operation at 1053 and 1058.4 nm is obtained, of which the maximum single pulse energy and peak power are 172.1 μJ and 26.1 kW, respectively, when the pulse width is 6.6 ns and the repetition rate is 4.3 kHz. A polarization property is observed, owing to the anisotropy of Cr:YAG. This stably Q-switched dual-wavelength laser is a good pump source for the generation of a terahertz wave at 1.53 THz. © 1965-2012 IEEE.


Wu D.,Tianjin University | Wu D.,Key Laboratory of Opto electronics Information Technology | Lu Q.,Tianjin University | Lu Q.,Key Laboratory of Opto electronics Information Technology | And 4 more authors.
Journal of Modern Optics | Year: 2014

The method of extracting the center coordinate of the light spot using the improved Gaussian fitting is presented to measure the thickness of oil film on water surface with differential laser trigonometry. The image of the light spot from the upper and lower surfaces of the oil film under measurement is extracted by the entropic threshold, and the center coordinate of the light spot is obtained by Gaussian fitting of the ascending edge and descending edge data of the light spot image extracted. Experimental measurement is carried out to verify the performance of the method. The range of the measurement is 0.1-10 mm and the maximum deviation between the nominal value and the measured value is less than ±23 μm for block gauges. The research results show that the algorithm presented in this paper is successful and feasible. © 2014 Taylor & Francis.


Li X.,Tianjin University | Li X.,Key Laboratory of Opto electronics Information Technology | Hu H.,Tianjin University | Hu H.,Key Laboratory of Opto electronics Information Technology | And 5 more authors.
Optics Express | Year: 2016

We consider the degree of linear polarization (DOLP) polarimetry system, which performs two intensity measurements at orthogonal polarization states to estimate DOLP. We show that if the total integration time of intensity measurements is fixed, the variance of the DOLP estimator depends on the distribution of integration time for two intensity measurements. Therefore, by optimizing the distribution of integration time, the variance of the DOLP estimator can be decreased. In this paper, we obtain the closed-form solution of the optimal distribution of integration time in an approximate way by employing Delta method and Lagrange multiplier method. According to the theoretical analyses and realworld experiments, it is shown that the variance of the DOLP estimator can be decreased for any value of DOLP. The method proposed in this paper can effectively decrease the measurement variance and thus statistically improve the measurement accuracy of the polarimetry system. © 2016 Optical Society of America.


Han J.,Tianjin University | Han J.,Key Laboratory of Opto electronics Information Technology | Lu Q.,Tianjin University | Lu Q.,Key Laboratory of Opto electronics Information Technology | And 5 more authors.
AIP Advances | Year: 2015

The light-induced refractive index change in Mn:KLTN crystal, illuminated by focused light sheet, is visualized in situ and quantified by digital holographic interferometry. By numerically retrieving a series of sequential phase maps from recording digital holograms, the spatial distribution of the induced refractive index change can be visualized and estimated readily. This technique enables the observation of the temporal evolution of the refractive index change under different recording situations such as writing laser power, applied voltage, and temperature, and the photoconductivity of Mn:KLTN crystal can be calculated as well, the experimental results are in good agreement with the theory. The research results suggest that the presented method is successful and feasible. © 2015 Author(s).


Tian Q.,Tianjin University | Tian Q.,Key Laboratory of Opto Electronics Information Technology | Yang Y.,Tianjin University | Yang Y.,Key Laboratory of Opto Electronics Information Technology | And 4 more authors.
Optics and Lasers in Engineering | Year: 2014

Laser line scanning 3D digitising systems have a wide range of applications. Their working performance is mainly determined by the system calibration procedure and is also affected by the working conditions, CCD camera imperfections, and object surface optical characteristics. Therefore, a comprehensive evaluation of working performance is necessary before and during use. This study proposes an experimental method for the performance evaluation of a laser line scanner (LLS) with 8 scanning sensors developed in our laboratory. This method first obtains the dense point clouds of standard parts composed of disks, cylinders, and squares. Next, the single-layer point clouds located in horizontal planes of different heights are fitted using the least squares method to obtain the enclosed contours S. Three parameters, namely, the standard deviation of the distance distribution between points and S, the mean distance of the distance distribution, and the shape feature sizes, are used to evaluate the performance. The proposed method evaluates both the scanner as a whole and each scanning sensor. Using this method, more comprehensive information can be acquired to evaluate the scanner performance. The experimental results show that the absolute dimension size error and relative error are less than 5 mm and 3%, respectively, and the relative shape error is less than 2%; therefore, the evaluated LLS system can meet the requirements for human anthropometry applications. Although each scanning sensor has different random and systematic error, these errors are the function of measurement depth. These conclusions are helpful for the further use of this scanner system and can be utilised to optimise this LLS system further. © 2013 Elsevier Ltd.

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