3,450 research outputs found
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CO2 conversion to phenyl isocyanates by uranium(vi) bis(imido) complexes.
Uranium(vi) trans-bis(imido) complexes [U(Îș4-{(tBu2ArO)2Me2-cyclam})(NPh)(NPhR)] react with CO2 to eliminate phenyl isocyanates and afford uranium(vi) trans-[O[double bond, length as m-dash]U[double bond, length as m-dash]NR]2+ complexes, including [U(Îș4-{(tBu2ArO)2Me2-cyclam})(NPh)(O)] that was crystallographically characterized. DFT studies indicate that the reaction proceeds by endergonic formation of a cycloaddition intermediate; the secondary reaction to form a dioxo uranyl complex is both thermodynamically and kinetically hindered
Detection of T cell cytokine production as a tool for monitoring immunotherapy
There are many complex relationships between tu-
mour cells and effector cells in the immune system.
These interactions are controlled predominantly by cy-
tokines, either within the tumour environment, or sys-
temically where the effector cells may be stimulated as
a response to the presence of the tumour. Favourable
clinical responses in cancer patients have been shown
to be associated with enhanced cell-mediated immunity
as well as T cell infiltration in tumours. This status
is controlled in part by a predominantly Th1 cytokine
profile e.g. IFN γ , TNF α and IL-12. Conversely, pa-
tients with advancing cancer may have impaired cell-
mediated immunity as a result of an imbalance of Th1
and Th2 cytokines e.g. IL-4 and IL-10 [6,9,15]. Whilst
cytokines have long been known to orchestrate the im-
mune system by allowing communication between reg-
ulatory and effector cells, the pleiotropic nature of these
molecules results in a very complex environment in
which to study any single moleculeâs properties. Several
in vitro protocols have been developed,which aim to closely reflect cytokine production and T cell function in vivo. However, these assays have been developed in artificial settings and as such only allow conclusions to be drawn within a defined context [11]. The aim of this report is to outline the basic proto-cols and applications for the detection of intracellular cytokines by flow cytometry, in the context of disease monitoring
Navigation Pattern Discovery from Internet Data
Electronic commerce sites need to learn as much as possible about their customers and those browsing their virtual premises, in order to maximize their marketing effort. The discovery of marketing related navigation patterns requires the development of data mining algorithms capable of discovering sequential access patterns from web logs. This paper introduces a new algorithm called MiDAS that extends traditional sequence discovery with a wide range of web-specific features. Domain knowledge is described as flexible navigation templates that can specify navigational behavior, as network structures for the capture of web site topologies, in addition to concept hierarchies and syntactic constraints. Unlike existing approaches, field dependency has been implemented, which allows the detection of sequences across monitored attributes, such as URLs and http referrers. Three different types of contained-in relationships are supported, which express different types of browsing behavior. The carried out experimental evaluation have shown promising results in terms of functionality as well as scalability.
Reference to the index of Ogilvie, McKenna & Morris, solicitors.
Appeals to Supreme Court 1931. Reports of appeal cases put to Supreme Court by A.G. Ogilvie or John Morris.
Rules of the Supreme Court 1856-1917. Printed orders bound into a volume for Gilmore & Clarke, solicitors, with ms list of contents
A saposin-lipoprotein nanoparticle system for membrane proteins.
A limiting factor in membrane protein research is the ability to solubilize and stabilize such proteins. Detergents are used most often for solubilizing membrane proteins, but they are associated with protein instability and poor compatibility with structural and biophysical studies. Here we present a saposin-lipoprotein nanoparticle system, Salipro, which allows for the reconstitution of membrane proteins in a lipid environment that is stabilized by a scaffold of saposin proteins. We demonstrate the applicability of the method on two purified membrane protein complexes as well as by the direct solubilization and nanoparticle incorporation of a viral membrane protein complex from the virus membrane. Our approach facilitated high-resolution structural studies of the bacterial peptide transporter PeptTSo2 by single-particle cryo-electron microscopy (cryo-EM) and allowed us to stabilize the HIV envelope glycoprotein in a functional state
Characteristics of stable flows over Southern Greenland
The main characteristic features of stable atmospheric flows over a large mountain plateau are summarised and then compared with mesoscale and synoptic scale numerical simulation, meteorological analysis, satellite imagery, and surface observations for the cases of flows over Southern Greenland for four wind directions. The detailed features are identified using the concepts and scaling of stably stratified flow over large mountains with variations in surface roughness, elevation, and heating. For westerly and easterly winds detached jets form at the southern tip, where coastal jets converge, which propagate large distances across the ocean. Near coasts katabatic winds can combine with barrier jets and wake flows generated by synoptic winds. Note how the approach flow rises/falls over southern Greenland for easterly/westerly winds, leading in both cases to more cloud on the western side. Some conclusions are drawn about the large-scale influences of these flows; detached jets in the atmosphere; air-sea interaction; formation of low pressure systems. For accurate simulations of these flows, mesoscale models are necessary with resolutions of order of 20 km or less. é BirkhÀuser Verlag, Basel, 2005
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Architecture of the AP2:clathrin coat on the membranes of clathrin-coated vesicles
AbstractClathrin-mediated endocytosis (CME) is crucial for modulating the protein composition of a cellâs plasma membrane. Clathrin forms a cage-like, polyhedral outer scaffold around a vesicle, to which cargo-selecting clathrin adaptors are attached. AP2 is the key adaptor in CME. Crystallography has shown AP2 to adopt a range of conformations. Here we used cryo-electron microscopy, tomography and subtomogram averaging to determine structures, interactions and arrangements of clathrin and AP2 at the key steps of coat assembly, from AP2 in solution to membrane-assembled clathrin-coated vesicles (CCVs). AP2 binds cargo and PtdIns(4,5)P2-containing membranes via multiple interfaces, undergoing conformational rearrangement from its cytosolic state. The binding mode of AP2 ÎČ2-appendage into the clathrin lattice in CCVs and buds implies how the adaptor structurally modulates coat curvature and coat disassembly.</jats:p
Considering the Case for Biodiversity Cycles: Reexamining the Evidence for Periodicity in the Fossil Record
Medvedev and Melott (2007) have suggested that periodicity in fossil
biodiversity may be induced by cosmic rays which vary as the Solar System
oscillates normal to the galactic disk. We re-examine the evidence for a 62
million year (Myr) periodicity in biodiversity throughout the Phanerozoic
history of animal life reported by Rohde & Mueller (2005), as well as related
questions of periodicity in origination and extinction. We find that the signal
is robust against variations in methods of analysis, and is based on
fluctuations in the Paleozoic and a substantial part of the Mesozoic.
Examination of origination and extinction is somewhat ambiguous, with results
depending upon procedure. Origination and extinction intensity as defined by RM
may be affected by an artifact at 27 Myr in the duration of stratigraphic
intervals. Nevertheless, when a procedure free of this artifact is implemented,
the 27 Myr periodicity appears in origination, suggesting that the artifact may
ultimately be based on a signal in the data. A 62 Myr feature appears in
extinction, when this same procedure is used. We conclude that evidence for a
periodicity at 62 Myr is robust, and evidence for periodicity at approximately
27 Myr is also present, albeit more ambiguous.Comment: Minor modifications to reflect final published versio
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