Direct functionalization of an optical fiber by a plasmonic nanosensor

We explore a rapid route for fabricating silver nanoparticles (NPs) at the end of an optical fiber. The size and number of silver NPs can be controlled by varying the exposure doses. The effect of the refractive index of different solvents on the extinction spectra have been studied as a proof of concept of a fiber integrated plasmon-based sensor.     

Glycan Reader: automated sugar identification and simulation preparation for carbohydrates and glycoproteins

Understanding how glycosylation affects protein structure, dynamics, and function is an emerging and challenging problem in biology. As a first step toward glycan modeling in the context of structural glycobiology, we have developed Glycan Reader and integrated it into the CHARMM-GUI, http://www.charmm-gui.org/input/glycan. Glycan Reader greatly simplifies the reading of PDB structure files containing glycans through (i) detection of carbohydrate molecules, (ii) automatic annotation of carbohydrates based on their three-dimensional structures, (iii) recognition of glycosidic linkages between carbohydrates as well as N-/O-glycosidic linkages to proteins, and (iv) generation of inputs for the biomolecular simulation program CHARMM with the proper glycosidic linkage setup. In addition, Glycan Reader is linked to other functional modules in CHARMM-GUI, allowing users to easily generate carbohydrate or glycoprotein molecular simulation systems in solution or membrane environments and visualize the electrostatic potential on glycoprotein surfaces. These tools are useful for studying the impact of glycosylation on protein structure and dynamics.     

Cathepsin L derived from skeletal muscle cells transfected with bFGF promotes endothelial cell migration

Gene transfer of basic fibroblast growth factor (bFGF) has been shown to induce significant endothelial migration and angiogenesis in ischemic disease models. Here, we investigate what factors are secreted from skeletal muscle cells (SkMCs) transfected with bFGF gene and whether they participate in endothelial cell migration. We constructed replication-defective adenovirus vectors containing the human bFGF gene (Ad/bFGF) or a control LacZ gene (Ad/LacZ) and obtained conditioned media, bFGF-CM and LacZ-CM, from SkMCs infected by Ad/bFGF or Ad/LacZ, respectively. Cell migration significantly increased in HUVECs incubated with bFGF-CM compared to cells incubated with LacZ-CM. Interestingly, HUVEC migration in response to bFGF-CM was only partially blocked by the addition of bFGF-neutralizing antibody, suggesting that bFGF-CM contains other factors that stimulate endothelial cell migration. Several proteins, matrix metalloproteinase-1 (MMP-1), plasminogen activator inhibitor-1 (PAI-1), and cathepsin L, increased in bFGF-CM compared to LacZ-CM; based on 1-dimensional gel electrophoresis and mass spectrometry. Their increased mRNA and protein levels were confirmed by RT-PCR and immunoblot analysis. The recombinant human bFGF protein induced MMP-1, PAI-1, and cathepsin L expression in SkMCs. Endothelial cell migration was reduced in groups treated with bFGF-CM containing neutralizing antibodies against MMP-1 or PAI-1. In particular, HUVECs treated with bFGF-CM containing cell-impermeable cathepsin L inhibitor showed the most significant decrease in cell migration. Cathepsin L protein directly promotes endothelial cell migration through the JNK pathway. These results indicate that cathepsin L released from SkMCs transfected with the bFGF gene can promote endothelial cell migration.     

N－N关联和有限核相对论平均场方法

密度有关的核子－介子相互作用耦合常数是在相对论平均场近似下用核物质的相对论Ｂｒｕｅｃｋｎｅｒ－Ｈａｒｔｒｅｅ－Ｆｏｃｋ近似计算的自能参数化得到的．这种密度有关的相互作用考虑了介质中Ｎ－Ｎ关联效应，用这种密度有关的相互作用来研究有限核的基态性质，如单粒子能级，平均结合能，电荷均方根半径，与实验值较好地符合，同时还与其它模型的结果进行了比较。     

A solid-phase approach to the phallotoxins: total synthesis of [Ala7]-phalloidin

Herein we report a solid-phase synthetic approach to [Ala7]-phalloidin (1). Prior syntheses of phallotoxins were carried out using solution-phase routes that required large scale and preclude library production. The route presented here consists of solution-phase preparation of key orthogonally protected amino acid building blocks, followed by a solid-phase peptide synthesis sequence, featuring two resin-bound macro-cyclization reactions. The final product mixture was composed of two atropisomeric compounds, one designated "natural" (1) and the other designated "non-natural" (1'). The structures of these species were modeled using restrained energy minimization with NMR-derived restraints.     

Facile, alternative synthesis of lanthanum phosphate nanocrystals by ultrasonication

Highly luminescent, rhabdophane (Ce(0.33)La(0.66))PO4.nH2O nanorods and nanoparticles were prepared in aqueous solutions by ultrasonication, at pH 1 and pH 12, respectively. Both nanorods (5 to 9 nm wide and several tens to several hundreds nm long) and nanoparticles (elongated, connected 5 nm particles) were as small and as uniform as products obtained from methods that utilize complexing agents or surfactants, only with no complexing agent. This method of synthesis by ultrasonication is a fast and simple method and it is expected to be applicable for the synthesis of other nanocrystalline lanthanide phosphates.     

A flexible synthesis of the phytoprostanes B1 type I and II

Syntheses of the enantiomerically pure phytoprostanes B(1) type I and II are described starting from furfural and n-propylfuran. Key steps include the preparation of the Freimanis (+/-)-hydroxycyclopentenone and Wittig coupling using chiral phosphonium salts.     

相对运动、集体振动、单粒子激发相互耦合系统输运过程的理论描述

考虑一个具有相对运动、内禀激发(包括集体振动、单粒子激发)相互耦合系统,在对相对运动做经典近似的条件下,并对内禀自由度采用与时间有关的投影算符方法,可以得到相对运动、集体振动及单粒子激发的耦合方程的一般理论形式。在一级玻恩近似和声子单粒子相互作用矩阵元的无规位相近似下,并忽略相对运动与声子单粒子之间相互作用高次项(只考虑到一次项),我们得到比较简单便于进行数值计算的耦合方程。这个理论适用于描述重离子深度非弹性散射,核裂变等核反应输运过程。     

Real-space observation of spectral degeneracy breaking in a waveguide-coupled disk microresonator

We report on the real-space observation of resonant frequency splitting in a high-Q waveguide-coupled silicon-on-insulator microdisk resonator. Phase sensitive near-field analysis reveals the stationary nature of the two resonant states, and spectral investigations clearly show their orthogonality. These measurements emphasize the role of the coupling waveguide in this splitting phenomenon. The symmetry of the two stationary whispering gallery modes is clearly observed and is found to follow the axial symmetry of the waveguide-coupled microdisk as it has been reported by earlier theoretical predictions.     

Scaling behavior of the first arrival time of a random-walking magnetic domain

We report a universal scaling behavior of the first arrival time of a traveling magnetic domain wall into a finite space-time observation window of a magneto-optical microscope enabling direct visualization of a Barkhausen avalanche in real time. The first arrival time of the traveling magnetic domain wall exhibits a nontrivial fluctuation and its statistical distribution is described by universal power-law scaling with scaling exponents of 1.34+/-0.07 for CoCr and CoCrPt films, despite their quite different domain evolution patterns. Numerical simulation of the first arrival time with an assumption that the magnetic domain wall traveled as a random walker well matches our experimentally observed scaling behavior, providing an experimental support for the random-walking model of traveling magnetic domain walls.