A new path in lighting and display: white light emitting diode with a single active layer

Light sources, especially white light sources, are indispensable and their development is strongly correlated with the progress of our technology-based society....     

Carbon nanothermometer containing gallium

Many applications have been found for carbon nanotubes, and we can now add a role as a 'nanothermometer' to this list. We describe how the height of a continuous, unidimensional column of liquid gallium inside a carbon nanotube (up to about 10 micrometres long and about 75 nanometres in diameter) varies linearly and reproducibly in the temperature range 50-500 degrees C, with an expansion coefficient that is the same as for gallium in the macroscopic state. We chose gallium as our thermal indicator because it has one of the greatest liquid ranges of any metal (29.78-2,403 degrees C) and a low vapour pressure even at high temperatures. This nanothermometer should be suitable for use in a wide variety of microenvironments.     

Cyclic AMP/GMP-dependent modulation of Ca2+ channels sets the polarity of nerve growth-cone turning

Signalling by intracellular second messengers such as cyclic nucleotides and Ca2+ is known to regulate attractive and repulsive guidance of axons by extracellular factors. However, the mechanism of interaction among these second messengers in determining the polarity of the guidance response is largely unknown. Here, we report that the ratio of cyclic AMP to cyclic GMP activities sets the polarity of netrin-1-induced axon guidance: high ratios favour attraction, whereas low ratios favour repulsion. Whole-cell recordings of Ca2+ currents at Xenopus spinal neuron growth cones indicate that cyclic nucleotide signalling directly modulates the activity of L-type Ca2+ channels (LCCs) in axonal growth cones. Furthermore, cGMP signalling activated by an arachidonate 12-lipoxygenase metabolite suppresses LCC activity triggered by netrin-1, and is required for growth-cone repulsion mediated by the DCC-UNC5 receptor complex. By linking cAMP and cGMP signalling and modulation of Ca2+ channel activity in growth cones, these findings delineate an early membrane-associated event responsible for signal transduction during bi-directional axon guidance.     

牙鲆贫血症病毒分离株的特性

用CHSE－214细胞，从患贫血症的牙鲆肾脏组织分离出一株病毒。电镜揭示为无囊膜、6面体、粒子直径约60nm；理化特性表明：病毒复制不受IUdR、BVdU的影响，对氯仿、乙醚不敏感性，热（60℃，30min）、酸（pH3．0，3h）中稳定；可被抗IPNV－Sp、Ab和VR－299株血清中和，其中抗Sp株血清的ND50为1:2560;病毒能在5～30℃增殖，最适为15～25℃；在盐度0．8～2．0％的培养液中，生长无明显差别；在16种鲑科和非鲑科鱼类细胞上，15℃培养1～4d出现CPE；感染细胞丫啶橙染色显示为黄绿色；用BirnavirusYAV株引物，PCR检出该病毒。结果提示该病毒株应属dsRNA的Birnavirus。     

Haploinsufficiency of NSD1 causes Sotos syndrome

We isolated NSD1 from the 5q35 breakpoint in an individual with Sotos syndrome harboring a chromosomal translocation. We identified 1 nonsense, 3 frameshift and 20 submicroscopic deletion mutations of NSD1 among 42 individuals with sporadic cases of Sotos syndrome. The results indicate that haploinsufficiency of NSD1 is the major cause of Sotos syndrome.     

Structural basis for semaphorin signalling through the plexin receptor

Semaphorins and their receptor plexins constitute a pleiotropic cell-signalling system that is used in a wide variety of biological processes, and both protein families have been implicated in numerous human diseases. The binding of soluble or membrane-anchored semaphorins to the membrane-distal region of the plexin ectodomain activates plexin's intrinsic GTPase-activating protein (GAP) at the cytoplasmic region, ultimately modulating cellular adhesion behaviour. However, the structural mechanism underlying the receptor activation remains largely unknown. Here we report the crystal structures of the semaphorin 6A (Sema6A) receptor-binding fragment and the plexin A2 (PlxnA2) ligand-binding fragment in both their pre-signalling (that is, before binding) and signalling (after complex formation) states. Before binding, the Sema6A ectodomain was in the expected 'face-to-face' homodimer arrangement, similar to that adopted by Sema3A and Sema4D, whereas PlxnA2 was in an unexpected 'head-on' homodimer arrangement. In contrast, the structure of the Sema6A-PlxnA2 signalling complex revealed a 2:2 heterotetramer in which the two PlxnA2 monomers dissociated from one another and docked onto the top face of the Sema6A homodimer using the same interface as the head-on homodimer, indicating that plexins undergo 'partner exchange'. Cell-based activity measurements using mutant ligands/receptors confirmed that the Sema6A face-to-face dimer arrangement is physiologically relevant and is maintained throughout signalling events. Thus, homodimer-to-heterodimer transitions of cell-surface plexin that result in a specific orientation of its molecular axis relative to the membrane may constitute the structural mechanism by which the ligand-binding 'signal' is transmitted to the cytoplasmic region, inducing GAP domain rearrangements and activation.     

Three-dimensional Simulation and Pattern Making of Collar Using Geometric Model

An algorithm is presented for computationally simulating collars and drafting patterns. The collar shape was modeled by three-dimensional Bezier patch. Changing the position of control points of the patch can interactively control the collar shape. Using triangular surface developing method, patterns of various styles of stand collar and separating collar were drafted. As the subsystem of 3D apparel design system, an interactive collar design system is constructed. To inspect the practical usage, we reproduced the collars using these patterns drafted by the interactive collar design system. Comparing with simulated collars, the system demonstrated well and we found it is more reliable and accurate than the method of handwork.     

Latent class DEDICOM

A probabilistic DEDICOM model was proposed for mobility tables. The model attempts to explain observed transition probabilities by a latent mobility table and a set of transition probabilities from latent classes to observed classes. The model captures asymmetry in observed mobility tables by asymmetric latent mobility tables. It may be viewed as a special case of both the latent class model and DEDICOM with special constraints. A maximum penalized likelihood (MPL) method was developed for parameter estimation. The EM algorithm was adapted for the MPL estimation. Two examples were given to illustrate the proposed method. The work reported in this paper has been supported by grant A6394 to the first author from the Natural Sciences and Engineering Research Council of Canada and by a fellowship of the Royal Netherlands Academy of Arts and Sciences to the second author. We would like to thank anonymous reviewers for their insightful comments.     

Recent Advances in High Efficiency Solar Cells

1 Results The conversion efficiency of sunlight to electricity is limited around 25%,when we use single junction solar cells. In the single junction cells,the major energy losses arise from the spectrum mismatching. When the photons excite carriers with energy well in excess of the bandgap,these excess energies were converted to heat by the rapid thermalization. On the other hand,the light with lower energy than that of the bandgap cannot be absorbed by the semiconductor,resulting in the losses. One way...