High Dynamic Range Digital Imaging of Spacecraft

The ability to capture engineering imagery with a wide degree of dynamic range during rocket launches is critical for post launch processing and analysis [USC03, NNC86]. Rocket launches often present an extreme range of lightness, particularly during night launches. Night launches present a two-fold problem: capturing detail of the vehicle and scene that is masked by darkness, while also capturing detail in the engine plume

Sterically restricted tin phosphines, stabilized by weak intramolecular donor-acceptor interactions

Funding: Engineering and Physical Sciences Research Council (EPSRC)Four related sterically restricted pen-substituted acenaphthenes have been prepared containing mixed tin phosphorus moieties in the proximal 5,6-positions (Acenap[SnR3][(PPr2)-Pr-i]; Acenap = acenaphthene-5,6-diyl; R-3 = Ph-3 (1), Ph2Cl (2), Me2Cl (3), Bu2Cl (4)). The degree of intramolecular P-Sn bonding within the series was investigated by X-ray crystallography, solution and solid-state NMR spectroscopy, and density functional theory (DFT/B3LYP/SBKJC/PCM) calculations. All members of the series adopt a conformation such that the phosphorus lone pair is located directly opposite the tin center, promoting an intramolecular donor acceptor P -> Sn type interaction. The extent of covalent bonding between Sn and P is found to be much greater in triorganotin chlorides 2-4 in comparison with the triphenyl derivative 1. Coordination of a highly electronegative chlorine atom naturally increases the Lewis acidity of the tin center, enhancing the Ip(P)-sigma*(Sn-Y) donor acceptor 3c-4e type interaction, as indicated by conspicuously short Sn-P peri distances and significant (1)J(P-31,Sn-119) spin spin coupling constants (SSCCs) in the range 740-754 Hz. Evidence supporting the presence of this interaction was also found in solid-state NMR spectra of some of the compounds which exhibit an indirect spin spin coupling on the same order of magnitude as observed in solution. DFT calculations confirm the increased covalent bonding between P and Sn in 2-4, with notable WBIs of ca. 0.35 obtained, in comparison to 0.1 in 1.PostprintPeer reviewe

Constrained phosphine chalcogenide selenoethers supported by peri-substitution

A series of phosphorus and selenium peri-substituted acenaphthene species with the phosphino group oxidized by O, S, and Se has been isolated and fully characterized, including by single-crystal X-ray diffraction. The P(V) and Se(II) systems showed fluxional behavior in solution due to the presence of two major rotamers, as evidenced with solution NMR spectroscopy. Using Variable-Temperature NMR (VT NMR) and supported by DFT (Density Functional Theory) calculations and solid-state NMR, the major rotamers in the solid and in solution were identified. All compounds showed a loss of the through-space JPSe coupling observed in the unoxidized P(III) and Se(II) systems due to the sequestration of the lone pair of the phosphine, which has been previously identified as the major contributor to the coupling pathway.Publisher PDFPeer reviewe

(Decacarbonyl)(1-isopropyl-2-phenyl-1,2,5,6-tetrahydroacenaphtho [5,6-cd][1,2]diphosphole)ditungsten(0) : Molbank

A binuclear tungsten(0) complex with an asymmetric bridging 1,2-diphosphole ligand was prepared by the photolysis of tungsten hexacarbonyl in the presence of 1-isopropyl-2-phenyl-1,2,5,6-tetrahydroacenaphtho [5,6-cd][1,2]diphosphole. The tungsten complex 1 was characterized by high resolution mass spectrometry, multinuclear NMR spectroscopy (1H, 13C, 31P), and elemental microanalysis. The structure of the trans isomer was resolved by single crystal X-ray diffraction, showing a slight elongation of the P−P bond upon coordination to the W(CO)5 groups.Publisher PDFPeer reviewe

Heteronuclear bimetallic complexes with 3d and 4f elements

Three heteronuclear bimetallic complexes [Cu(MeOH)(L)Ln(NO3)3] ( 1-Ce ; Ln = Ce, 1-Pr ; Ln = Pr, and 1-Nd ; Ln = Nd) were prepared using H2L (1,3-bis[(3-methoxysalicylidene)amino]-2,2-dimethylpropane) in methanol, affording the complexes as green crystalline materials. These can be prepared in a one-pot synthesis from 2,2-dimethylpropan-1,3-diamine, o-vanillin, copper(II) nitrate, and Ln(III) nitrate (Ln = Ce, Pr, Nd). X-ray crystallography, high-resolution mass spectrometry, and UV-vis spectroscopy were used to characterize the bimetallic complexes. All three complexes showed the copper center adopting a five-coordinate square pyramidal geometry and the lanthanoid cation adopting a ten-coordinate geometry.Publisher PDFPeer reviewe

Optimised synthesis and characterisation of 1-adamantyltrimethylphosphonium iodide

This work was financially supported by the EPSRC (grant numbers EP/L505079/1 and EP/M506631/1) and COST action SM1302 SIPs. The authors thank the University of St Andrews NMR Service and the EPSRC UK National Mass Spectrometry Facility at Swansea University (NMSF).A synthetic route to multigram quantities of 1-adamantyltrimethylphosphonium iodide is reported. The synthesis starts from the commercially available precursor 1-adamantyl bromide and was optimised with respect to yield and ease of purification. The title compound is of interest to zeolite chemists as a potent organic structure-directing agent. Full spectroscopic characterisation data of all isolated intermediates and single crystal X-ray diffraction data of AdP(O)Cl2, [AdPMe2H]I and [AdPMe3]I (Ad = 1-adamantyl) are reported.PostprintPeer reviewe

(9R,9aS,12aR,13S)-9,13-Diphenyl-9,9a,12a,13-tetrahydro-9,13-methanotriphenyleno[2,3-c]furan-10,12,14-trione

X-ray crystallography was used to characterise the title compound for the first time, and the 1H NMR, 13C NMR and IR spectroscopic data from earlier reports were also updated.Publisher PDFPeer reviewe

The core clock gene, Bmal1, and its downstream target, the SNARE regulatory protein secretagogin, are necessary for circadian secretion of glucagon-like peptide-1.

OBJECTIVES:The incretin hormone glucagon-like peptide-1 (GLP-1) is secreted from intestinal L-cells upon nutrient intake. While recent evidence has shown that GLP-1 is released in a circadian manner in rats, whether this occurs in mice and if this pattern is regulated by the circadian clock remain to be elucidated. Furthermore, although circadian GLP-1 secretion parallels expression of the core clock gene Bmal1, the link between the two remains largely unknown. Secretagogin (Scgn) is an exocytotic SNARE regulatory protein that demonstrates circadian expression and is essential for insulin secretion from β-cells. The objective of the current study was to establish the necessity of the core clock gene Bmal1 and the SNARE protein SCGN as essential regulators of circadian GLP-1 secretion. METHODS:Oral glucose tolerance tests were conducted at different times of the day on 4-hour fasted C57BL/6J, Bmal1 wild-type, and Bmal1 knockout mice. Mass spectrometry, RNA-seq, qRT-PCR and/or microarray analyses, and immunostaining were conducted on murine (m) and human (h) primary L-cells and mGLUTag and hNCI-H716 L-cell lines. At peak and trough GLP-1 secretory time points, the mGLUTag cells were co-stained for SCGN and a membrane-marker, ChIP was used to analyze BMAL1 binding sites in the Scgn promoter, protein interaction with SCGN was tested by co-immunoprecipitation, and siRNA was used to knockdown Scgn for GLP-1 secretion assay. RESULTS:C57BL/6J mice displayed a circadian rhythm in GLP-1 secretion that peaked at the onset of their feeding period. Rhythmic GLP-1 release was impaired in Bmal1 knockout (KO) mice as compared to wild-type controls at the peak (p < 0.05) but not at the trough secretory time point. Microarray identified SNARE and transport vesicle pathways as highly upregulated in mGLUTag L-cells at the peak time point of GLP-1 secretion (p < 0.001). Mass spectrometry revealed that SCGN was also increased at this time (p < 0.001), while RNA-seq, qRT-PCR, and immunostaining demonstrated Scgn expression in all human and murine primary L-cells and cell lines. The mGLUTag and hNCI-H716 L-cells exhibited circadian rhythms in Scgn expression (p < 0.001). The ChIP analysis demonstrated increased binding of BMAL1 only at the peak of Scgn expression (p < 0.01). Immunocytochemistry showed the translocation of SCGN to the cell membrane after stimulation at the peak time point only (p < 0.05), while CoIP showed that SCGN was pulled down with SNAP25 and β-actin, but only the latter interaction was time-dependent (p < 0.05). Finally, Scgn siRNA-treated cells demonstrated significantly blunted GLP-1 secretion (p < 0.01) in response to stimulation at the peak time point only. CONCLUSIONS:These data demonstrate, for the first time, that mice display a circadian pattern in GLP-1 secretion, which is impaired in Bmal1 knockout mice, and that Bmal1 regulation of Scgn expression plays an essential role in the circadian release of the incretin hormone GLP-1

Systematic reviews: a cross-sectional study of location and citation counts

BACKGROUND: Systematic reviews summarize all pertinent evidence on a defined health question. They help clinical scientists to direct their research and clinicians to keep updated. Our objective was to determine the extent to which systematic reviews are clustered in a large collection of clinical journals and whether review type (narrative or systematic) affects citation counts. METHODS: We used hand searches of 170 clinical journals in the fields of general internal medicine, primary medical care, nursing, and mental health to identify review articles (year 2000). We defined 'review' as any full text article that was bannered as a review, overview, or meta-analysis in the title or in a section heading, or that indicated in the text that the intention of the authors was to review or summarize the literature on a particular topic. We obtained citation counts for review articles in the five journals that published the most systematic reviews. RESULTS: 11% of the journals concentrated 80% of all systematic reviews. Impact factors were weakly correlated with the publication of systematic reviews (R(2 )= 0.075, P = 0.0035). There were more citations for systematic reviews (median 26.5, IQR 12 – 56.5) than for narrative reviews (8, 20, P <.0001 for the difference). Systematic reviews had twice as many citations as narrative reviews published in the same journal (95% confidence interval 1.5 – 2.7). CONCLUSIONS: A few clinical journals published most systematic reviews. Authors cited systematic reviews more often than narrative reviews, an indirect endorsement of the 'hierarchy of evidence'

A European multi-language initiative to make the general population aware of independent clinical research: the European Communication on Research Awareness Need project

BACKGROUND: The ECRAN (European Communication on Research Awareness Needs) project was initiated in 2012, with support from the European Commission, to improve public knowledge about the importance of independent, multinational, clinical trials in Europe. METHODS: Participants in the ECRAN consortium included clinicians and methodologists directly involved in clinical trials; researchers working in partnership with the public and patients; representatives of patients; and experts in science communication. We searched for, and evaluated, relevant existing materials and developed additional materials and tools, making them freely available under a Creative Commons licence. RESULTS: The principal communication materials developed were: 1. A website ( http://ecranproject.eu ) in six languages, including a Media centre section to help journalists to disseminate information about the ECRAN project 2. An animated film about clinical trials, dubbed in the 23 official languages of the European Community, and an interactive tutorial 3. An inventory of resources, available in 23 languages, searchable by topic, author, and media type 4. Two educational games for young people, developed in six languages 5. Testing Treatments interactive in a dozen languages, including five official European Community languages 6. An interactive tutorial slide presentation testing viewers' knowledge about clinical trials CONCLUSIONS: Over a 2-year project, our multidisciplinary and multinational consortium was able to produce, and make freely available in many languages, new materials to promote public knowledge about the importance of independent and international clinical trials. Sustained funding for the ECRAN information platform could help to promote successful recruitment to independent clinical trials supported through the European Clinical Research Infrastructure Network