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BackgroundThe pathogenesis of depression remains not fully understood， and previous studies have suggested that the kynurenine pathway （KP） plays an important role in the pathogenesis of major depressive disorder.ObjectiveTo study the difference in serum KP metabolites level between patients with first-episode and recurrent major depressive disorder， and to testify the correlation between KP metabolites level with the severity of depressive symptoms， so as to provide references for the prevention of recurrence.MethodsA total of 136 patients with major depressive disorder who attended the outpatient clinics of the Affiliated Brain Hospital of Guangzhou Medical University from November 2016 to December 2018 and met the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders， fifth edition （DSM-5） diagnostic criteria were included， including 62 patients in the first-episode group and 74 patients in the recurrent group. Meanwhile， 60 healthy subjects were included as control group. All patients were assessed by Hamilton Depression Scale-17 item （HAMD-17）， and serum concentrations of tryptophan （TRP）， kynurenine （KYN） and kynurenic acid （KYNA） were measured by liquid chromatography tandem mass spectrometry （LC-MS/MS）. Then the correlation of HAMD-17 total score and individual item scores with the levels of KP metabolites was tested using partial correlation coefficient.ResultsCompared with the control group， the first-episode group and recurrent group showed a marked decline in TRP concentration （t=-3.044， -4.477， P

ObjectiveTo explore the differences of cognitive function in patients with treatment-resistant depression and drug-naive first-episode major depressive disorder， and to examine the relationship between severity of clinical symptoms and cognitive function， so as to provide references for prognosis improvement.MethodsFrom November 2016 to December 2019， 119 patients with drug-naive first-episode major depressive disorder and 82 patients with treatment-resistant depression in a hospital in Guangzhou were enrolled， meantime， another 71 healthy individuals recruited from the community were set as healthy control group. Clinical symptoms were assessed using Hamilton Depression Scale-17 item （HAMD-17） and Hamilton Anxiety Scale （HAMA）. Cognitive domains， including speed of processing， working memory， verbal learning and memory， and visual learning and memory were measured with the MATRICS Consensus Cognitive Battery （MCCB）. Multiple covariance analysis was used to compare the differences in cognitive function among three groups. Thereafter， partial correlation analysis was performed within patient groups to explore the relationship of HAMD-17/HAMA score with the four dimensions of MCCB.ResultsThe speed of processing， visual learning and memory scores of treatment-resistant depression group and drug-naive first-episode depression group were lower than those of healthy control group， and the working memory score of the treatment-resistant depression group was lower than that of the healthy control group， with statistical significance （P0.05）.ConclusionCompared with drug-naive first-episode major depressive disorder patients and healthy controls， the impairments of speed of processing， visual learning and memory are more severe in patients with treatment-resistant depression. Moreover， the cognitive function impairment in patients with drug-naive first-episode major depressive disorder and treatment-resistant depression has no correlation with the severity of depressive and anxious symptoms.

ObjectiveTo explore the anhedonia level and its relationship with cognitive function in patients with first-episode psychosis， and to analyze the influencing factors of cognitive function.MethodsA total of 143 first-episode psychiatric patients who met the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders， fifth edition （DSM-5） in the Affiliated Brain Hospital of Guangzhou Medical University from December 2016 to March 2019 were selected. Positive and Negative Syndrome Scale （PANSS） was used to evaluate the patient’s psychiatric symptoms， in which N2 （emotional withdrawal） and N4 （passive/apathetic social withdrawal） were used to assess the anhedonia level， and patients whose （N2+N4） scores beyond 4 were classified into anhedonia group， and those with （N2+N4） scores less than or equal to 4 were classified into non-anhedonia group. Hamilton Depression Scale-24 item （HAMD-24） was used to measure the depressive symptoms， and the MATRICS Consensus Cognitive Battery （MCCB） was used to detect cognitive function. Then the clinical symptoms and cognitive function of two groups were compared， and the influencing factors of cognitive function were screened by multiple linear regression analysis.ResultsThe negative symptom score， general pathological symptom score and total score of PANSS in anhedonia group were significantly higher than those of non-anhedonia group， with statistical difference （P

Observation of the backscattering form function for a solid polymethylmeth-acrylate(PMMA) sphere reveals a significant enhancement at low frequencies, which is associated with the subsonic Rayleigh waves resonance. The presence of these resonances suggests that solid PMMA spheres may be used as passive sonar targets for certain applications.The slightly deformed PMMA spheres with regular corrugation are constructed for studying and manipulating the low-frequency resonances of subsonic Rayleigh waves. For the regular-corrugated PMMA spheres, the first-order approximate of Rayleigh normal mode solution is obtained with the perturbation method and the backscattering form function is analyzed in each order. It can be found that coupling among multiple resonance modes is introduced by the boundary deformation and leads to the shift of resonance frequency. An approximate formula for the frequency shift with respect to the parameters of corrugated boundary is deduced. Based on this formula, it is possible to evaluate resonance frequency of subsonic Rayleigh waves quickly and then manipulate acoustic scattering filed of the slightly deformed PMMA spheres in water passively.

Focusing on the problems of target deformation, occlusion, background interference and rotation, a robust video tracking method is proposed in this paper, which is based on the superpixels and dynamic graph matching. Firstly, to make the superpixels edge fit better and structure tighter, the local gradient feature is fused into the simple linear iterative clustering (SLIC) method. Secondly, the candidate target superpixels set is generated by Graph Cuts and to obtain more accurate foreground superpixels set, the LASVM classification results are fused into the Graph Cuts energy function. Thirdly, in order to make the proposed tracker more robust, the color local entropy is fused into the diagonal elements of the affinity matrix. Experiment results show that the proposed algorithm has strong robustness and better tracking accuracy.

This study investigated the influence of various types of Chinese metalinguistic awareness on spelling through the mediation of character reading and copying, using a path model with young Chinese as a second language (CSL) learners. A total of 221 Grade 3 Hong Kong ethnic minority students were given a range of measures including Chinese spelling, orthographic awareness, phonological awareness, morphological awareness, character reading, copying, and listening comprehension. The path model fitted well with the data and accounted for a substantial 83% of the variance in spelling. This showed that, controlling for listening comprehension, (1) both orthographic awareness and morphological awareness, but not phonological awareness, contributed to character reading, which had a dominant direct influence ([beta] = 0.74) on spelling; (2) only orthographic awareness contributed to copying, which had a statistically significant, though comparatively slim, direct influence on spelling ([beta] = 0.10), and (3) other than the aforementioned indirect influences, orthographic awareness also had a direct effect on spelling ([beta] = 0.18). Given the complexity of Chinese orthography, Chinese spelling in CSL learners likely depends on (1) high-quality mental representations of characters and good visual--motor integration, which are reflected in good character reading and copying, and related to both orthographic awareness and morphological awareness, and (2) orthographic awareness is a critical component skill facilitating spelling directly and indirectly.

The present study aimed to examine the contributions of two separate Pinyin skills and oral vocabulary to Chinese word reading of 70 third graders in a U.S. Mandarin Immersion program where Pinyin was introduced at Grade 3. Hierarchical regression analyses showed that Pinyin initial-final spelling--the skill to spell Chinese syllables using Pinyin letters--and oral vocabulary were uniquely associated with Chinese word reading, after accounting for the effects of phonological awareness and the other Pinyin skill of tone identification. The variance in Chinese word reading explained by tone identification was fully accounted for by oral vocabulary, Pinyin initial--final spelling, and phonological awareness, suggesting that tone identification might involve both phonology- and meaning-related processes. Oral vocabulary and tone identification explained more shared variance in Chinese word reading than the two code-related skills of phonological awareness and Pinyin initial-final spelling. The importance of meaning-related skills in learning the deep orthography of Chinese characters for Chinese L2 young learners is discussed.