Cobalt‐Exchanged Poly(Heptazine Imides) as Transition Metal–Nx Electrocatalysts for the Oxygen Evolution Reaction

Poly(heptazine imides) hosting cobalt ions as countercations are presented as promising electrocatalysts for the oxygen evolution reaction (OER). A facile mixed‐salt melt‐assisted condensation is developed to prepare such cobalt poly(heptazine imides) (PHI‐Co). The Co ions can be introduced in well‐controlled amounts using this method, and are shown to be atomically dispersed within the imide‐linked heptazine matrix. When applied to electrocatalytic OER, PHI‐Co shows a remarkable activity with an overpotential of 324 mV and Tafel slope of 44 mV dec−1 in 1 m KOH.DFG, 390540038, EXC 2008: UniSysCatTU Berlin, Open-Access-Mittel - 202

Preparation of highly and generally enriched mammalian tissues for solid state NMR.

An appreciable level of isotope labelling is essential for future NMR structure elucidation of mammalian biomaterials, which are either poorly expressed, or unexpressable, using micro-organisms. We present a detailed protocol for high level (13)C enrichment even in slow turnover murine biomaterials (fur keratin), using a customized diet supplemented with commercial labelled algal hydrolysate and formulated as a gel to minimize wastage, which female mice consumed during pregnancy and lactation. This procedure produced approximately eightfold higher fur keratin labelling in pups, exposed in utero and throughout life to label, than in adults exposed for the same period, showing both the effectiveness, and necessity, of this approach.The authors would like to acknowledge funding from the Biotechnology and Biological Sciences Research Council for DGR and RR; Engineering and Physical Sciences Research Council for WYC and VWCW; National Institute of Health Research for RAB.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s10858-015-9977-

New record of the Japanese seahorse Hippocampus mohnikei Bleeker, 1853 (Syngnathiformes: Syngnathidae) in Hong Kong waters

Funding: This study was supported by the Consultancy Project (AFCD/SQ/13/17) of the Agriculture, Fisheries and Conservation Department of the Government of the Hong Kong SAR and the Collaborative Research Fund (C7013-19G) of the Hong Kong Research Grants Council.A new record of Hippocampus mohnikei Bleeker, 1853 was confirmed in Hong Kong through morphological and molecular identification. It is highly possible that there is an established population of H. mohnikei in Hong Kong due to continuous sightings by citizen scientists in the past nine years. The record is significant from a biogeographical perspective as it connects the distributions of known populations in northern China and Japan to those spanning Thailand to India. This further affirms the status of Hong Kong as a hotspot for seahorse biodiversity and conservation in China.Publisher PDFPeer reviewe

Primase-based whole genome amplification

In vitro DNA amplification methods, such as polymerase chain reaction (PCR), rely on synthetic oligonucleotide primers for initiation of the reaction. In vivo, primers are synthesized on-template by DNA primase. The bacteriophage T7 gene 4 protein (gp4) has both primase and helicase activities. In this study, we report the development of a primase-based Whole Genome Amplification (pWGA) method, which utilizes gp4 primase to synthesize primers, eliminating the requirement of adding synthetic primers. Typical yield of pWGA from 1 ng to 10 ng of human genomic DNA input is in the microgram range, reaching over a thousand-fold amplification after 1 h of incubation at 37°C. The amplification bias on human genomic DNA is 6.3-fold among 20 loci on different chromosomes. In addition to amplifying total genomic DNA, pWGA can also be used for detection and quantification of contaminant DNA in a sample when combined with a fluorescent reporter dye. When circular DNA is used as template in pWGA, 108-fold of amplification is observed from as low as 100 copies of input. The high efficiency of pWGA in amplifying circular DNA makes it a potential tool in diagnosis and genotyping of circular human DNA viruses such as human papillomavirus (HPV)

Proline provides site-specific flexibility for in vivo collagen.

Fibrillar collagens have mechanical and biological roles, providing tissues with both tensile strength and cell binding sites which allow molecular interactions with cell-surface receptors such as integrins. A key question is: how do collagens allow tissue flexibility whilst maintaining well-defined ligand binding sites? Here we show that proline residues in collagen glycine-proline-hydroxyproline (Gly-Pro-Hyp) triplets provide local conformational flexibility, which in turn confers well-defined, low energy molecular compression-extension and bending, by employing two-dimensional 13C-13C correlation NMR spectroscopy on 13C-labelled intact ex vivo bone and in vitro osteoblast extracellular matrix. We also find that the positions of Gly-Pro-Hyp triplets are highly conserved between animal species, and are spatially clustered in the currently-accepted model of molecular ordering in collagen type I fibrils. We propose that the Gly-Pro-Hyp triplets in fibrillar collagens provide fibril "expansion joints" to maintain molecular ordering within the fibril, thereby preserving the structural integrity of ligand binding sites.BBSRC, EPSRC, Raymond and Beverly Sackler Fund for Physics of Medicine, Wellcome Trust, ER

Pigmentation Chemistry and Radical-Based Collagen Degradation in Alkaptonuria and Osteoarthritic Cartilage

Alkaptonuria (AKU) is a rare disease characterized by high levels of homogentisic acid (HGA); patients suffer from tissue ochronosis: dark brown pigmentation, especially of joint cartilage, leading to severe early osteoarthropathy. No molecular mechanism links elevated HGA to ochronosis; the pigment's chemical identity is still not known, nor how it induces joint cartilage degradation. Here we give key insight on HGA-derived pigment composition and collagen disruption in AKU cartilage. Synthetic pigment and pigmented human cartilage tissue both showed hydroquinone-resembling NMR signals. EPR spectroscopy showed that the synthetic pigment contains radicals. Moreover, we observed intrastrand disruption of collagen triple helix in pigmented AKU human cartilage, and in cartilage from patients with osteoarthritis. We propose that collagen degradation can occur via transient glycyl radicals, the formation of which is enhanced in AKU due to the redox environment generated by pigmentation

An International Collaborative Consensus Statement on En Bloc Resection of Bladder Tumour Incorporating Two Systematic Reviews, a Two-round Delphi Survey and a Consensus Meeting

Funding/Support and role of the sponsor: This study was supported by the General Research Fund/Early Career Scheme of the Research Grants Council, Hong Kong, China (reference no. 24116518).Peer reviewedPostprin

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

'Making room': squatter clearance in Hong Kong, 1945-1999

published_or_final_versionHousing ManagementMasterMaster of Housing Managemen