Synthetic approaches for accessing rare-earth analogues of UiO-66

Rare-earth (RE) analogues of UiO-66 with non-functionalised 1,4-benzenedicarboxylate linkers are synthesised for the first time, and a series of synthetic approaches is provided to troubleshoot the synthesis. RE-UiO-66 analogues are fully characterised, and demonstrate a high degree of crystallinity, high surface area and thermal stability, consistent with the UiO-66 archetype

Rational Synthesis of Mixed-Metal Microporous Metal–Organic Frameworks with Controlled Composition Using Mechanochemistry

Mechanochemistry enables targeted, rapid synthesis of bimetallic metal−organic frameworks (MOFs) with a controlled 1:1 stoichiometric composition of metal nodes. In particular, ball milling enabled the use of specifically synthesized solid coordination complexes of Zn(II), Mg(II), Ni(II), and Co(II) for the assembly of a range of microporous mixed-metal MOF-74 materials composed of pairs of d-block or main group metals in a predetermined 1:1 stoichiometric ratio, including ZnMg-, ZnCo-, ZnCu-, MgZn-, MgCo-, NiZn-, NiMg-, NiCo-, CoZn-, CoMg-, CoCu-, and MgCa-MOF-74. By using specifically prepared precursors in the ynthesis of diverse mixed-metal MOF-74 targets, this rational synthesis represents the first entry of mechanochemistry into the target-oriented synthesis of mixed- metal MOFs

Benign by Design: Green and Scalable Synthesis of Zirconium UiO-Metal–Organic Frameworks by Water-Assisted Mechanochemistry

We present a solvent-free, green, and rapid mechanochemical route for the synthesis of a series of zirconium metal–organic frameworks (MOFs) composed of Zr6 cluster nodes, UiO-66, UiO-66-NH2, MOF-801, and MOF-804, both on a laboratory scale and by scalable and flow mechanochemical processing. The methodology, based on the use of a nonconventional zirconium dodecanuclear acetate cluster and a minute amount of water as an additive, affords high-quality MOFs in less than 1 h of milling, with minimal requirements for workup processing and eliminating the need for conventional hazardous solvents, such as dimethylformamide. Moreover, the use of a dodecanuclear zirconium acetate precursor circumvents the need for modulators resulting in acetic acid as the only byproduct of the reaction, which does not harm these acid-resistant materials. The porosity, thermal and chemical stability, as well as catalytic activity of mechanochemically prepared Zr-based MOFs are similar to those of solvothermally synthesized counterparts. Finally, the synthesis is readily applicable on a 10 g scale by using a planetary mill, and is also performed by solid-state flow synthesis using twin-screw extrusion (TSE), affording more than 100 g of catalytically active UiO-66-NH2 material in a continuous process at a rate of 1.4 kg/h

Bottom-up construction of a superstructure in a porous uranium-organic crystal

Bottom-up construction of highly intricate structures from simple building blocks remains one of the most difficult challenges in chemistry. We report a structurally complex, mesoporous uranium-based metal-organic framework (MOF) made from simple starting components. The structure comprises 10 uranium nodes and seven tricarboxylate ligands (both crystallographically nonequivalent), resulting in a 173.3-angstrom cubic unit cell enclosing 816 uranium nodes and 816 organic linkers—the largest unit cell found to date for any nonbiological material. The cuboctahedra organize into pentagonal and hexagonal prismatic secondary structures, which then form tetrahedral and diamond quaternary topologies with unprecedented complexity. This packing results in the formation of colossal icosidodecahedral and rectified hexakaidecahedral cavities with internal diameters of 5.0 nanometers and 6.2 nanometers, respectively—ultimately giving rise to the lowest-density MOF reported to date

Green and rapid mechanosynthesis of high-porosity NU- and UiO-type metal–organic frameworks

The use of a dodecanuclear zirconium acetate cluster as a precursor enables the rapid, clean mechanochemical synthesis of high-microporosity metal–organic frameworks NU-901 and UiO-67, with surface areas up to 2250 m2 g−1. Real-time X-ray diffraction monitoring reveals that mechanochemical reactions involving the conventional hexanuclear zirconium methacrylate precursor are hindered by the formation of an inert intermediate, which does not appear when using the dodecanuclear acetate cluster as a reactant

Structure, function and diversity of the healthy human microbiome

Author Posting. © The Authors, 2012. This article is posted here by permission of Nature Publishing Group. The definitive version was published in Nature 486 (2012): 207-214, doi:10.1038/nature11234.Studies of the human microbiome have revealed that even healthy individuals differ remarkably in the microbes that occupy habitats such as the gut, skin and vagina. Much of this diversity remains unexplained, although diet, environment, host genetics and early microbial exposure have all been implicated. Accordingly, to characterize the ecology of human-associated microbial communities, the Human Microbiome Project has analysed the largest cohort and set of distinct, clinically relevant body habitats so far. We found the diversity and abundance of each habitat’s signature microbes to vary widely even among healthy subjects, with strong niche specialization both within and among individuals. The project encountered an estimated 81–99% of the genera, enzyme families and community configurations occupied by the healthy Western microbiome. Metagenomic carriage of metabolic pathways was stable among individuals despite variation in community structure, and ethnic/racial background proved to be one of the strongest associations of both pathways and microbes with clinical metadata. These results thus delineate the range of structural and functional configurations normal in the microbial communities of a healthy population, enabling future characterization of the epidemiology, ecology and translational applications of the human microbiome.This research was supported in part by National Institutes of Health grants U54HG004969 to B.W.B.; U54HG003273 to R.A.G.; U54HG004973 to R.A.G., S.K.H. and J.F.P.; U54HG003067 to E.S.Lander; U54AI084844 to K.E.N.; N01AI30071 to R.L.Strausberg; U54HG004968 to G.M.W.; U01HG004866 to O.R.W.; U54HG003079 to R.K.W.; R01HG005969 to C.H.; R01HG004872 to R.K.; R01HG004885 to M.P.; R01HG005975 to P.D.S.; R01HG004908 to Y.Y.; R01HG004900 to M.K.Cho and P. Sankar; R01HG005171 to D.E.H.; R01HG004853 to A.L.M.; R01HG004856 to R.R.; R01HG004877 to R.R.S. and R.F.; R01HG005172 to P. Spicer.; R01HG004857 to M.P.; R01HG004906 to T.M.S.; R21HG005811 to E.A.V.; M.J.B. was supported by UH2AR057506; G.A.B. was supported by UH2AI083263 and UH3AI083263 (G.A.B., C. N. Cornelissen, L. K. Eaves and J. F. Strauss); S.M.H. was supported by UH3DK083993 (V. B. Young, E. B. Chang, F. Meyer, T. M. S., M. L. Sogin, J. M. Tiedje); K.P.R. was supported by UH2DK083990 (J. V.); J.A.S. and H.H.K. were supported by UH2AR057504 and UH3AR057504 (J.A.S.); DP2OD001500 to K.M.A.; N01HG62088 to the Coriell Institute for Medical Research; U01DE016937 to F.E.D.; S.K.H. was supported by RC1DE0202098 and R01DE021574 (S.K.H. and H. Li); J.I. was supported by R21CA139193 (J.I. and D. S. Michaud); K.P.L. was supported by P30DE020751 (D. J. Smith); Army Research Office grant W911NF-11-1-0473 to C.H.; National Science Foundation grants NSF DBI-1053486 to C.H. and NSF IIS-0812111 to M.P.; The Office of Science of the US Department of Energy under Contract No. DE-AC02-05CH11231 for P.S. C.; LANL Laboratory-Directed Research and Development grant 20100034DR and the US Defense Threat Reduction Agency grants B104153I and B084531I to P.S.C.; Research Foundation - Flanders (FWO) grant to K.F. and J.Raes; R.K. is an HHMI Early Career Scientist; Gordon&BettyMoore Foundation funding and institutional funding fromthe J. David Gladstone Institutes to K.S.P.; A.M.S. was supported by fellowships provided by the Rackham Graduate School and the NIH Molecular Mechanisms in Microbial Pathogenesis Training Grant T32AI007528; a Crohn’s and Colitis Foundation of Canada Grant in Aid of Research to E.A.V.; 2010 IBM Faculty Award to K.C.W.; analysis of the HMPdata was performed using National Energy Research Scientific Computing resources, the BluBioU Computational Resource at Rice University

A framework for human microbiome research

A variety of microbial communities and their genes (the microbiome) exist throughout the human body, with fundamental roles in human health and disease. The National Institutes of Health (NIH)-funded Human Microbiome Project Consortium has established a population-scale framework to develop metagenomic protocols, resulting in a broad range of quality-controlled resources and data including standardized methods for creating, processing and interpreting distinct types of high-throughput metagenomic data available to the scientific community. Here we present resources from a population of 242 healthy adults sampled at 15 or 18 body sites up to three times, which have generated 5,177 microbial taxonomic profiles from 16S ribosomal RNA genes and over 3.5 terabases of metagenomic sequence so far. In parallel, approximately 800 reference strains isolated from the human body have been sequenced. Collectively, these data represent the largest resource describing the abundance and variety of the human microbiome, while providing a framework for current and future studies

Evolution of extensively drug-resistant tuberculosis over four decades: whole genome sequencing and dating analysis of Mycobacterium tuberculosis isolates from KwaZulu-Natal.

CAPRISA, 2015.Abstract available in pdf