Yi Zhang

Ultra-high isotropic resolution imaging of retinal structures was made possible with an adaptive optics system using dual deformable mirrors and a Fourier-domain optical coherence tomography system with correction for longitudinal chromatic aberration. This system was used to image microscopic retinal structures of healthy as well as diseased retinas in vivo. The improved resolution and contrast enhanced visualization of morphological structures in the retina can be clearly seen. The benefits of this instrument are apparent from comparison of new images with those acquired using a previous generation AO-OCT instrument. Big change in the appearance of speckle field can be observed as well. Additionally, further improvements in volumetric data acquisition and image representation will be discussed. This includes creation of large Field of View AO-OCT volume from multiple sub-volumes and its visualization. Also techniques and results of reducing speckle contrast by averaging multiple B-scans will be presented.

© 2015 American Institute of Chemical Engineers.Current lithium-ion batteries are predicted to be unable to provide the specific energy required to meet the ever-increasing demands of rapidly emerging technologies. Due to a high theoretical specific capacity of 1675 mAh/g, sulfur has gained much attention as a promising positive electrode material for high specific energy rechargeable batteries. Although the lithium/sulfur cell has been studied for many years and continues to receive much attention today as an alternative power source for zero-emission vehicles and advanced electronic devices, the realization of this novel cell's promise as a commercial product has yet to be successful. The major problems with sulfur electrodes involve: the dissolution of sulfur and the resulting diffusion of dissolved polysulfides and the deposition of insulating products on both the negative and the positive electrodes. These solid deposits can physically block the electrode reaction sites, thus passivating the electrode surfaces. Another important problem is the large volume change that occurs with the conversion of S to Li 2 S. It is important to understand that the performance of Li/S cells is hampered by linked chemical and mechanical degradations and both degradation mechanisms must be correctly alleviated in order to markedly improve current-technology Li/S cells. In this study, improved cycling performance via the reactive functional groups on graphene oxide to successfully immobilize sulfur and lithium polysulfides during operation has been demonstrated. The use of a new electrolyte and binder leads to improved cell performance in terms of high-rate capability and good reversibility, yielding at least 800 cycles have also been demonstrated.

Oxidative stress has been implicated in cardiac arrhythmia, although a causal relationship remains undefined. We have recently demonstrated a marked up-regulation of NADPH oxidase isoform 4 in patients with atrial fibrillation, which is accompanied by overproduction of reactive oxygen species. In this study, we investigated the impact on the cardiac phenotype of NOX4 overexpression in zebrafish. One-cell stage embryos were injected with NOX4 RNA prior to video recording of a GFP-labeled beating heart in real time at 24-31 h post-fertilization. Intriguingly, NOX4 embryos developed cardiac arrhythmia that is characterized by irregular heartbeats. When quantitatively analyzed by an established LQ-1 program, the NOX4 embryos displayed much more variable beat-to-beat intervals. Both the phenotype and the increased ROS in NOX4 embryos were attenuated by NOX4 morpholino co-injection, treatments of the embryos with polyethylene glycol-conjugated superoxide dismutase, or NOX4 inhibitors fulvene-5, 6-dimethylaminofulvene, and proton sponge blue. Injection of NOX4-P437H mutant RNA had no effect on the cardiac phenotype or ROS production. In addition, phosphorylation of calcium/cal-modulin-dependent protein kinase II was increased in NOX4 embryos but diminished by polyethylene glycol-conjugated superoxide dismutase, whereas its inhibitor KN93 or AIP abolished the arrhythmic phenotype. Taken together, our data for the first time uncover a novel pathway that underlies the development of cardiac arrhythmia, namely NOX4 activation, subsequent NOX4-specific NADPH-driven ROS production, and redox-sensitive CaMKII activation. These findings may ultimately lead to novel therapeutics targeting cardiac arrhythmia. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Lithium/sulfur cells are receiving significant attention as an alternative power source for zero-emission vehicles and advanced electronic devices due to the very high theoretical specific capacity of the sulfur cathode. However, the poor cycle life and rate capability have remained a grand challenge, preventing the practical application of this attractive technology. Here, we report that a Li/S cell employing a cetyltrimethyl ammonium bromide -modified sulfur-graphene oxide nanocomposite cathode can be discharged at rates as high as 6C and charged at rates as high as 3C while still maintaining high specific capacity, with a long cycle life exceeding 1500 cycles and an extremely low decay rate, perhaps the best performance demonstrated so far for a Li/S cell. The initial estimated cell-level specific energy of our cell was ∼500 W·h/kg, which is much higher than that of current Li-ion cells. Even after 1500 cycles, we demonstrate a very high specific capacity, which corresponds to ∼414 mA·h/g of electrode: still higher than state-of-the-art Li-ion cells. Moreover, these Li/S cells with lithium metal electrodes can be cycled with an excellent Coulombic efficiency of 96.3% after 1500 cycles, which was enabled by our new formulation of the ionic liquid-based electrolyte. The performance we demonstrate herein suggests that Li/S cells may already be suitable for high-power applications such as power tools. Li/S cells may now provide a substantial opportunity for the development of zero-emission vehicles with a driving range similar to that of gasoline vehicles. © 2013 American Chemical Society.

Previous research has consistently demonstrated the importance of parents' expectations and adolescents' expectations on adolescents' academic achievement. Less is known, however, about the reciprocal relationships among these constructs. To address this issue, we analyzed two waves of data from the National Education Longitudinal Study of 1988 using longitudinal cross-lagged path models. The sample consisted of 14,376 students. Results indicated that there was a reciprocal relationship between parents' expectations and adolescents' expectations. Moreover, there was a reciprocal relationship between expectations and adolescents' academic achievement. Multiple-group analyses of gender and ethnicity revealed that the effects of parents' expectations on students' expectations were stronger among males than among females. With respect to ethnic differences, the effects of adolescents' expectations were weakest on parents' expectations among African Americans as compared to the other ethnic groups. Implications of these findings are discussed. © 2010 The Author.

Frontotemporal dementia and Alzheimers disease are sometimes difficult to differentiate clinically because of overlapping symptoms. Using diffusion tensor imaging measurements of fractional anisotropy can be useful in distinguishing the different patterns of white matter degradation between the two dementias. In this study, we performed MRI scans in a 4 Tesla MRI machine including T1-weighted structural images and diffusion tensor images in 18 patients with FTD, 18 patients with Alzheimers disease and 19 cognitively normal controls. FA was measured selectively in specific fibre tracts as well as globally in a voxel-by-voxel analysis. Patients with FTD were associated with reductions of FA in frontal and temporal regions including the anterior corpus callosum, bilateral anterior, descending cingulum tracts, and uncinate tracts, compared to controls. Patients with Alzheimers disease were associated with reductions of FA in parietal, temporal and frontal regions including the left anterior and posterior cingulum tracts, bilateral descending cingulum tracts and left uncinate tracts compared to controls. When compared with Alzheimers disease, FTD was associated with greater reductions of FA in frontal brain regions, whereas no region in Alzheimers disease showed greater reductions of FA when compared to FTD. In conclusion, the regional patterns of anisotropy reduction in FTD and Alzheimers disease compared to controls suggest a characteristic distribution of white matter degradation in each disease. Moreover, the white matter degradation seems to be more prominent in FTD than in Alzheimers disease. Taken together, the results suggest that white matter degradation measured with DTI may improve the diagnostic differentiation between FTD and Alzheimers disease.

Background: Endothelins are paracrine peptides with growth-promoting and vasoactive functions for a variety of cell types. Elevated activation of the endothelin signaling pathway induces cell proliferation and/or survival and is implicated in a variety of malignancies. Increased endothelin 1 was described in solar lentigines in previous reports, raising the possibility that the endothelin pathway may be of significance in keratinocyte proliferation-related disorders. However, detailed investigation on endothelins in skin malignancies is lacking. Objectives: This study aims to survey the expression of endothelins and their receptors in keratinocyte-derived benign and malignant tumors of the skin and to test the effects of endothelin inhibitors on the growth and survival of cultured keratinocytes. Methods: Quantitative polymerase chain reaction was used to measure the level of gene transcription of three endothelins and two endothelin receptors. The genes with significant messenger ribonucleic acid expression abnormalities were confirmed with immunohistochemical analysis to examine expression differences at the protein levels. To analyze the effect of endothelin inhibitors on the keratinocyte growth and survival, keratinocytes were cultured in the presence of various concentrations of endothelin inhibitors and subjected to tetrazolium bromide assay to quantify the cell numbers over time. Results: ET-1 mRNA was found to be significantly up-regulated in seborrheic keratosis and basal cell carcinoma. However, no significant expression increase was found in actinic keratosis, Bowen's disease, or squamous cell carcinoma. Immunohistochemical analysis of ET-1 peptide confirmed increased expression. In cultured keratinocytes, peptide inhibitors of the endothelin pathway resulted in a marked reduction in cell survival. Conclusion: The endothelin signaling pathway, especially ET-1, is activated in basoloid keratinocyte neoplasms of the skin, such as basal cell carcinoma and seborrheic keratosis. Blockade of this pathway can reduce cell survival in vitro. Therefore, endothelin inhibitors potentially offer a novel method for the treatment of some keratinocyte-derived skin tumors.

As the younger generation, who like to pursue novelty and excitement, becomes the main consumer and the traditional consumption culture changes in China, the blind box has become a popular product among young people with its uncertain characteristics. Previous studies have mainly explored the role of uncertainty in promotion, while this paper focuses on the role of uncertainty in daily sales of blind box products. Based on the stimulus–organism–response theory, this paper conducted an online questionnaire survey and an empirical analysis in China, which examined the mechanism of the positive impact of uncertainty and the moderating effect of consumption purpose. The results show that uncertainty affects consumers’ purchase intention mainly through affecting their emotional value, which is one dimension of perceived value; consumer purpose also moderates the effect of uncertainty on perceived value, and the effect of perceived value on purchase intention. The results of this study are not only of great significance for understanding the uncertain marketing and blind box products, but also have management implications for enterprises to make use of the uncertain marketing.

This study examines how chief executive officer overconfidence can influence the quantity, quality and direction of corporate innovation using Chinese firms for the period 2009–2016. Our results suggest that overall, CEO overconfidence has a positive impact on firm innovation productivity. Furthermore, this effect is significant for Chinese non-SOEs but not for Chinese SOEs. Specifically, an overconfident CEO can facilitate firm innovation in new technological areas but not in the firm’s existing areas. Additionally, we find that internal controls can regulate the relationship between CEO overconfidence and innovation. Interestingly, when the internal control level is too high or too low, the correlation between CEO overconfidence and innovation productivity is not significant.

Wang Ming and the pursuit of poetic beauty show other Tang poets, the pastoral poetry, from the clever to the shape of early words, becomes the Xing as exquisite mood to create. Wang specializes in the performance of the empty mountains, the quiet beauty, Meng Cheng in the writing scene in rivers and lakes of pure pale superior; to Wang Meng as the center, forming a landscape of poetry similar to Tang Poetry. His poetry, recluse by the wind and Zen influenced thinking, feelings are willing to lonely landscape of silent contemplation and meditation into one, God will in the matter, over into the Zen can be heard on the air in quiet turbulence, the blazing plain deep. There is a dilute ethereal ethereal charm. Poetry is considered authentic ancient landscape

The time-scale dynamic equations play an important role in modeling complex dynamical processes. In this paper, the Mei symmetry and new conserved quantities of time-scale Birkhoff’s equations are studied. The definition and criterion of the Mei symmetry of the Birkhoffian system on time scales are given. The conditions and forms of new conserved quantities which are found from the Mei symmetry of the system are derived. As a special case, the Mei symmetry of time-scale Hamilton canonical equations is discussed and new conserved quantities for the Hamiltonian system on time scales are derived. Two examples are given to illustrate the application of results.

© 2016 IOP Publishing Ltd.Few-layer thick MoSe2 and WSe2 possess non-trivial spin textures with sizable spin splitting due to the inversion symmetry breaking embedded in the crystal structure and strong spin-orbit coupling. We report a spin-resolved photoemission study of MoSe2 and WSe2 thin film samples epitaxially grown on a bilayer graphene substrate. We only found spin polarization in the single-and trilayer samples-not in the bilayer sample-mostly along the out-of-plane direction of the sample surface. The measured spin polarization is found to be strongly dependent on the light polarization as well as the measurement geometry, which reveals intricate coupling between the spin and orbital degrees of freedom in this class of material.

Guanxi in China is a very ancient concept embedded in the Confucian concept of life and one that is a ‚hot' topic in that it is currently attracting increasing attention from both Western and Chinese scholars. One aspect of Guanxi which has been the subject of most of the research of late is the influence of Guanxi on firm performance. However, relatively few studies have examined how Guanxi at the individual level is transferred into a firm to influence its financial performance. This study first reclassifies Guanxi into obligatory, reciprocal, and utilitarian types at the individual level as a means to clarifying the confusion brought above from previous studies. It then provides a conceptual framework in which to systematically characterize the link between Guanxi at the individual level and organizational dynamics: that is, how is Guanxi at the individual level shifted to a firm and how does it affect organizational dynamics of that firm at the organizational level. Finally, it provides a deeper understanding of the financial implications of Guanxi to business firms in China.

"The Voice of the Tang Dynasty," the strong voice of the times, the pride of Tang, Gao Bing in "Poetry is the sound" touted in the "Rhythm pure finish" is a refined aesthetic qualities of Tang poetry, established the Ming Dynasty. " Tang poetry must be "the aesthetic ideal. Ming Tang on the physical tone, trying to implement Sheng Tang wonderful rhyme poems for the rule-based method, resulting in obtaining the fur and missing the spirit of the abuse. If designed as Fengshen on the rise and poetry, the Tang Dynasty dance sound of high performance flow away life Charm, can directly show the reader the feeling and imagination, just like the sound of the air, the flower of the mirror is a difficult to explain in words of rhyme outside the cause, that is charm. The poetry of Prime Tang Dynasty, because of based on both rhythm and spirit, was believed the pure sound of Tang Voice. GAO Bing regarded "pure sound" as the aesthetic characteristic, and set up the artistic ideal of Ming Dynasty, which poems renown in the Prime Dynasty. From the stylistic mode, Ming People interpreted the voice of Prime Tang Dynasty into the poetry rhythm, but it resulted that spirit of poem was lost. From the romantic charm, they emphasized brilliance life spirit of the Prime Tang poetry, and made it to be the artistic state that difficult to arrive