Study of Ni/Al Interface Diffusion by Molecular Dynamics Simulation

Molecular dynamics simulation of Ni/Al interface diffusion is carried out by Embedded Atom Method (EAM) potential. The problem how the temperature affects Ni/Al interface diffusion is discussed. The initial dynamic behavior of Ni/Al interface diffusion at high temperature is shown. The study in this letter is helpful to understand the origin of diffusion phenomenon.

Analysis of the Spectral Resolution of a TeO2 based Noncollinear Acousto-Optic Tunable Filter

The spectral resolution is a main index of evaluating the performance of the designed acousto-optic tunable filter (AOTF). In this letter, an accurate expression of the spectral resolution is presented by considering both the birefringence and the rotatory property of TeO2 crystal. The deduced expression is significant in improving the accuracy of the design of an AOTF and pushing the development of the high-performance AOTF.

基于AOTF和LCVR的全偏振反射成像研究

文中提出了一种AOTF与双LCVR相结合的光谱偏振反射成像系统。通过对近景树叶上的病变组织进行单色光成像,获取stokes参量图像,并对图像进行了优化,使得图像细节清晰可见。结果表明,该系统可以对近景物体进行反射光谱偏振成像,为后续进一步研究不同物体表面反射偏振成像提供了可行性.

舌象分析便携式声光高光谱成像技术

本研究提出一种基于窄带声光可调滤波和光纤内窥技术的高光谱成像方法并用于舌象研究。在实验上实时地获得了可见光波段被测舌体的一系列精细图像和光谱信息。研究结果体现了较高的图像分辨率和光谱分辨率。提出的方法能够为舌诊的客观化研究提供有效的光学手段。

大孔拟薄水铝石和γ-Al_(2)O_(3)载体制备研究进展

γ-Al_(2)O_(3)作为催化剂载体在炼油领域具有广泛应用。随着原油资源的重、劣质化,重油加工过程,如固定床渣油加氢、重油催化裂化,对其催化剂载体均提出了大孔要求以满足重油大分子在催化剂孔道内的传质扩散所需,因此,制备适用于重油加工的大孔γ-Al_(2)O_(3)载体受到越来越多的关注。γ-Al_(2)O_(3)性质主要决定于其前驱物拟薄水铝石,本工作综述了大孔拟薄水铝石的主要工业制备工艺,包括沉淀法、醇铝水解法等,并介绍了基于上述工艺所进行的γ-Al_(2)O_(3)载体扩孔研究,如pH摆动扩孔、添加扩孔剂扩孔及水热处理扩孔等。最后,展望了今后大孔拟薄水铝石和γ-Al_(2)O_(3)载体制备研究的重点和发展方向。

A new class of luminescent nanoprobes based on main-group Sb^(3+) emitters

Inorganic luminescent nanocrystals(NCs)doped with main-group ns^(2)-metal ions have evoked tremendous interest in many technological fields owing to their superior optical properties.Herein,we report a new class of luminescent nanoprobes based on 5s2-metal Sb3+-doped CaS NCs that are excitable by using a near ultraviolet light-emitting diode.The optical properties and excited-state dynamics of Sb3+in CaS NCs are comprehensively surveyed through temperature-dependent steady-state and transient photoluminescence(PL)spectroscopies.Owing to the strong electron-phonon coupling of Sb^(3+)in CaS NCs,Sb3+ions experience a dynamic Jahn-Taller distortion on the excited state,which results in bright green PL of Sb3+with a broad emission band,a large Stokes shift,and a high PL quantum yield up to 17.3%.By taking advantage of the intense PL of Sb^(3+),we show in proof-of-concept experiments the application of biotinylated CaS:Sb^(3+)NCs as sensitive luminescent nanoprobes for biotin receptor-targeted cancer cell imaging and zebrafish imaging with a high imaging contrast.These findings provide fundamental insights into the excited-state dynamics of Sb^(3+)in CaS NCs,thus laying a foundation for future design of novel and versatile luminescent nanoprobes via main-group ns2-metal doping.

TCP7 functions redundantly with several Class Ⅰ TCPs and regulates endoreplication in Arabidopsis

TCP(TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR) proteins, a family of plantspecific transcription factors, play important roles in many developmental processes. However, genetic and functional redundancy among class I TCP limits the analysis of their biological roles. Here, we identified a dominantnegative mutant of Arabidopsis thaliana TCP7 named leaf curling-upward(lcu), which exhibits smaller leaf cells and shorter hypocotyls than the wild type, due to defective endoreplication. A septuple loss-of-function mutant of TCP7, TCP8, TCP14, TCP15, TCP21, TCP22, and TCP23 displayed similar developmental defects to those of lcu.Genome-wide RNA-sequencing showed that lcu and the septuple mutant share many misexpressed genes.Intriguingly, TCP7 directly targets the CYCLIN D1;1 (CYCD1;1) locus and activates its transcription. We determined that the C-terminus of TCP7 accounts for its transcriptional activation activity. Furthermore, the mutant protein LCU exhibited reduced transcriptional activation activity due to the introduction of an EAR-like repressive domain at its C-terminus. Together, these observations indicate that TCP7 plays important roles during leaf and hypocotyl development, redundantly, with at least six class I TCPs, and regulates the expression of CYCD1;1 to affect endoreplication in Arabidopsis.

Brain of the blind:transcriptomics of the golden-line cavefish brain

The genus Sinocyclocheilus (golden-line barbel) includes 25species of cave-dwelling blind fish (cavefish)and more than 30 surface-dwelling species with normal vision.Cave environments are dark and generally nutrient-poor with few predators.Cavefish of several genera evolved convergent morphological adaptations in visual,pigmentation,brain,olfactory,and digestive systems. We compared brain morphology and gene expression patterns in a cavefish Sinocyclocheilus anophthalmus with those of a closely related surface-dwelling species S.angustiporus.Results showed that cavefish have a longer olfactory tract and a much smaller optic tectum than surface fish.Transcriptomics by RNA-seq revealed that many genes upregulated in cavefish are related to lysosomes and the degradation and metabolism of proteins,amino acids,and lipids.Genes down- regulated in cavefish tended to involve "activation of gene expression in cholesterol biosynthesis" and cholesterol degradation in the brain.Genes encoding Srebfs (sterol regulatory element- binding transcription factors)and Srebf targets,including enzymes in cholesterol synthesis,were downregulated in cavefish brains compared with surface fish brains.The gene encoding Cyp46a1, which eliminates cholesterol from the brain,was also downregulated in cavefish brains,while the total level of cholesterol in the brain remained unchanged.Cavefish brains misexpressed several genes encoding proteins in the hypothalamus-pituitary axis,including Trh,Sst,Crh,Pomc,and Mc4r.These results suggest that the rate of lipid biosynthesis and breakdown may both be depressed in golden-line cavefish brains but that the lysosome recycling rate may be increased in cavefish;properties that might be related to differences in nutrient availability in caves.

Differentially-expressed opsin genes identified in Sinocyclocheilus cavefish endemic to China

Eye degeneration is a common troglomorphic character of cave-dwelling organisms. Comparing the morphology and molecular biology of cave species and their close surface relatives is a powerful tool for studying regressive eye evolution and other adaptive phenotypes. We compared two co-occurring and closely-related species of the fish genus Sinocyclocheilus, which is endemic to China and includes both surface- and cave-dwelling species. Sinocyclocheilus tileihornes, a cave species, had smaller eyes than Sinocyclocheilus angustiporus, a surface species. Histological and immunohistochemical analyses revealed that the cave- fish had shorter cones and more disorderly rods than did the surface-dwelling species. Using quantitative PCR and in situ hybri- dization, we found that rhodopsin and a long-wavelength sensitive opsin had significantly lower expression levels in the cavefish. Furthermore, one of two short-wavelength-sensitive opsins was expressed at significantly higher levels in the cavefish. Changes in the expression ofopsin genes may have played a role in the degeneration of cavefish eyes [Current Zoology 59 （2）： 170-174, 2013].

Phylogenetic analysis and expression differences of eye-related genes in cavefish genus Sinocyclocheilus

The adaptive evolution of visual systems has been observed in many cavefish.However,little is known about the molecular mechanisms underlying these adaptations,which include regressive changes such as eye degeneration.Here,we analyzed phylogenetic and expression patterns of 6 eye-related genes(crx,foxg1b,opn1sw2,otx2,rho and sox2)in 12 Sinocyclocheilus species from China,including 8 stygobionts and 4 stygophiles,and examined photoreceptor cell morphology of these species.Those eye-degenerated species of Sinocyclocheilus were polyphyletic and showed different degrees of photoreceptor defects in responses to cave environments.The eye loss and degeneration are the result of convergent evolution.Although S.anophthalmus grouped with the eye-normal species,it displayed not only a high degree of eye degeneration but also significant expression differences in eyerelated genes compared with the eye-normal species.The gene foxg1b,which was determined to be under positive selection,might play an important role in the process of eye degeneration in S.anophthalmus based on differential expression.Eye-related gene expression and selection may have contributed to the polyphyly of the cave species.We examined gene expression and duplication in 6 eye-related genes and revealed that these genes displayed considerable diversity in relative expression in Sinocyclocheilus fishes.Otx2 and sox2 were significantly up-regulated in individual cave species,while the other 4 genes(crx,foxg1b,opn1sw2 and rho)were significantly down-regulated.These findings provide a valuable resource for elucidating molecular mechanisms associated with visual system evolution in cavefish.