伦敦两大学院蕴酿合并组成科研巨人

在经过一阵激烈波动以后,伦敦两所最大的科研机构——伦敦大学学院(UCL)和皇家学院公开宣称它们正在蕴酿一项合并计划,该计划的目的是为了更有效地与美国科研机构展开竞争。     

A route to high surface area, porosity and inclusion of large molecules in crystals

One of the outstanding challenges in the field of porous materials is the design and synthesis of chemical structures with exceptionally high surface areas. Such materials are of critical importance to many applications involving catalysis, separation and gas storage. The claim for the highest surface area of a disordered structure is for carbon, at 2,030 m2 g(-1) (ref. 2). Until recently, the largest surface area of an ordered structure was that of zeolite Y, recorded at 904 m2 g(-1) (ref. 3). But with the introduction of metal-organic framework materials, this has been exceeded, with values up to 3,000 m2 g(-1) (refs 4-7). Despite this, no method of determining the upper limit in surface area for a material has yet been found. Here we present a general strategy that has allowed us to realize a structure having by far the highest surface area reported to date. We report the design, synthesis and properties of crystalline Zn4O(1,3,5-benzenetribenzoate)2, a new metal-organic framework with a surface area estimated at 4,500 m2 g(-1). This framework, which we name MOF-177, combines this exceptional level of surface area with an ordered structure that has extra-large pores capable of binding polycyclic organic guest molecules--attributes not previously combined in one material.     

Tyrosine kinase receptor RET is a key regulator of Peyer's patch organogenesis

Normal organogenesis requires co-ordinate development and interaction of multiple cell types, and is seemingly governed by tissue specific factors. Lymphoid organogenesis during embryonic life is dependent on molecules the temporal expression of which is tightly regulated. During this process, haematopoietic 'inducer' cells interact with stromal 'organizer' cells, giving rise to the lymphoid organ primordia. Here we show that the haematopoietic cells in the gut exhibit a random pattern of motility before aggregation into the primordia of Peyer's patches, a major component of the gut-associated lymphoid tissue. We further show that a CD45+CD4-CD3-Il7Ralpha-c-Kit+CD11c+ haematopoietic population expressing lymphotoxin has an important role in the formation of Peyer's patches. A subset of these cells expresses the receptor tyrosine kinase RET, which is essential for mammalian enteric nervous system formation. We demonstrate that RET signalling is also crucial for Peyer's patch formation. Functional genetic analysis revealed that Gfra3-deficiency results in impairment of Peyer's patch development, suggesting that the signalling axis RET/GFRalpha3/ARTN is involved in this process. To support this hypothesis, we show that the RET ligand ARTN is a strong attractant of gut haematopoietic cells, inducing the formation of ectopic Peyer's patch-like structures. Our work strongly suggests that the RET signalling pathway, by regulating the development of both the nervous and lymphoid system in the gut, has a key role in the molecular mechanisms that orchestrate intestine organogenesis.