12,026 research outputs found
Ureteropelvic junction obstruction caused by metastatic cholangiocarcinoma
We describe the rare case of a 61-year-old female with right ureteropelvic junction (UPJ) obstruction caused by metastatic cholangiocarcinoma. Her past medical history was notable for cholangiocarcinoma treated with neoadjuvant chemoradiation and two orthotopic liver transplants six years earlier. Urology was consulted when she presented with flank pain and urinary tract infection. Diagnostic workup demonstrated right UPJ obstruction. She was managed acutely with percutaneous nephrostomy. She subsequently underwent robotic pyeloplasty and intrinsic obstruction of the UPJ was discovered. Histological examination revealed adenocarcinoma, consistent with systemic recurrence of the patient\u27s known cholangiocarcinoma
A molecular superfluid: non-classical rotations in doped para-hydrogen clusters
Clusters of para-hydrogen (pH2) have been predicted to exhibit superfluid
behavior, but direct observation of this phenomenon has been elusive. Combining
experiments and theoretical simulations, we have determined the size evolution
of the superfluid response of pH2 clusters doped with carbon dioxide (CO2).
Reduction of the effective inertia is observed when the dopant is surrounded by
the pH2 solvent. This marks the onset of molecular superfluidity in pH2. The
fractional occupation of solvation rings around CO2 correlates with enhanced
superfluid response for certain cluster sizes
Package Deal: The Economic Impacts of Recycling Standards for Packaging in Massachusetts
The Island Foundation, The Jessie B. Cox Charitable Trust, The Charles Stuart Mott Foundation, The New England Biolabs Foundation, Haymarket People's Fund, The Jewish Communal Fund of New Yor
Spreading in Social Systems: Reflections
In this final chapter, we consider the state-of-the-art for spreading in
social systems and discuss the future of the field. As part of this reflection,
we identify a set of key challenges ahead. The challenges include the following
questions: how can we improve the quality, quantity, extent, and accessibility
of datasets? How can we extract more information from limited datasets? How can
we take individual cognition and decision making processes into account? How
can we incorporate other complexity of the real contagion processes? Finally,
how can we translate research into positive real-world impact? In the
following, we provide more context for each of these open questions.Comment: 7 pages, chapter to appear in "Spreading Dynamics in Social Systems";
Eds. Sune Lehmann and Yong-Yeol Ahn, Springer Natur
Synthesis and Characterization of 3,5-Bis(di-tert-butylphosphinito)pyridine Pincer Complexes
The synthesis of some “reverse pyridine” bis(phosphinite) pincer complexes of nickel and rhodium is reported. N-Functionalization of a POCOP ligand with a borane Lewis acid was found to permit cyclometalation with metal precursors, which reacted with the free base ligand in an undesired manner. Convenient removal of the coordinated Lewis acid was accomplished using polymer-supported 4-dimethylaminopyridine. The effects of borane Lewis acid coordination on the physical and spectroscopic properties of the pincer complexes were also assessed
Synthesis and Characterization of 3,5-Bis(di-tert-butylphosphinito)pyridine Pincer Complexes
The synthesis of some “reverse pyridine” bis(phosphinite) pincer complexes of nickel and rhodium is reported. N-Functionalization of a POCOP ligand with a borane Lewis acid was found to permit cyclometalation with metal precursors, which reacted with the free base ligand in an undesired manner. Convenient removal of the coordinated Lewis acid was accomplished using polymer-supported 4-dimethylaminopyridine. The effects of borane Lewis acid coordination on the physical and spectroscopic properties of the pincer complexes were also assessed
Differences in transmission properties and susceptibility to long-term depression reveal functional specialization of ascending axon and parallel fiber synapses to Purkinje cells
An understanding of the patterns of mossy fiber transmission to Purkinje cells, via granule cell axons, is fundamental to models of cerebellar cortical signaling and processing. Early theories assumed that mossy fiber input is widely disseminated across the cerebellar cortex along beams of parallel fibers, which spread for several millimeters across the cerebellar cortex. Direct evidence for this has, however, proved controversial, leading to the development of an alternative hypothesis that mossy fiber inputs to the cerebral cortex are in fact vertically organized such that the ascending segment of the granule axon carries a greater synaptic weight than the parallel fiber segment. Here, we report that ascending axon synapses are selectively resistant to cerebellar long-term depression and that they release transmitter with higher mean release probabilities and mean quantal amplitudes than parallel fiber synapses. This novel specialization of synapses formed by different segments of the same axon not only explains the reported patterns of granule cell→ Purkinje cell transmission across the cerebellar cortex but also reveals an additional level of functionality and complexity of cerebellar processing. Consequently, ascending axon synapses represent a new element of cortical signal processing that should be distinguished from parallel fiber synapses in future experimental and theoretical studies of cerebellar function
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