568 research outputs found
Experimental Results on Heavy Quarks
This paper reviews the results presented at the 31st ICHEP on Heavy Quarks,
with emphasis on those related to the determinationof the unitarity triangle
parameters.Comment: Plenary talk given at 31st ICHEP, Amserdam, 24-31 July 200
A multipurpose machine to study paramagnetic species on well defined single crystal surfaces
A new ultrahigh vacuum (UHV) electron paramagnetic resonance (EPR)
spectrometer operating at 94 GHz to investigate paramagnetic centers on single
crystal surfaces is described. It is particularly designed to study
paramagnetic centers on well-defined model catalysts using epitaxial thin
oxide films grown on metal single crystals. The EPR setup is based on a
commercial Bruker E600 spectrometer, which is adapted to ultrahigh vacuum
conditions using a home made Fabry Perot resonator. The key idea of the
resonator is to use the planar metal single crystal required to grow the
single crystalline oxide films as one of the mirrors of the resonator. EPR
spectroscopy is solely sensitive to paramagnetic species, which are typically
minority species in such a system. Hence, additional experimental
characterization tools are required to allow for a comprehensive investigation
of the surface. The apparatus includes a preparation chamber hosting
equipment, which is required to prepare supported model catalysts. In
addition, surface characterization tools such as low energy electron
diffraction (LEED)/Auger spectroscopy, temperature programmed desorption
(TPD), and infrared reflection absorption spectroscopy (IRAS) are available to
characterize the surfaces. A second chamber used to perform EPR spectroscopy
at 94 GHz has a room temperature scanning tunneling microscope attached to it,
which allows for real space structural characterization. The heart of the UHV
adaptation of the EPR experiment is the sealing of the Fabry-Perot resonator
against atmosphere. To this end it is possible to use a thin sapphire window
glued to the backside of the coupling orifice of the Fabry Perot resonator.
With the help of a variety of stabilization measures reducing vibrations as
well as thermal drift it is possible to accumulate data for a time span, which
is for low temperature measurements only limited by the amount of liquid
helium. Test measurements show that the system can detect paramagnetic species
with a density of approximately 5 × 1011 spins/cm2, which is comparable to the
limit obtained for the presently available UHV-EPR spectrometer operating at
10 GHz (X-band). Investigation of electron trapped centers in MgO(001) films
shows that the increased resolution offered by the experiments at W-band
allows to identify new paramagnetic species, that cannot be differentiated
with the currently available methodology
Acute lung injury after aortic surgery: the relation between lung and leg microvascular permeability to III Indium-labeled transferin and circulating mediators
Code and its image: the functions of text and visualisation in a code-based design studio
Traditionally, design learning in the architecture studio has taken place through a combination of individual work and joint projects. The introduction of code-based design practices in the design studio has altered this balance, introducing new models of joint authorship and new ways for individuals to contribute to co-authored projects. This paper presents a case study describing four design studios in a higher education setting that used code as a tool for generating architectural geometry. The format of the studios encouraged the students to reflect critically on their role as authors and to creatively address the multiple opportunities for shared authorship available with code-based production. The research question addressed in this study involved the role of code-based practices in altering the model of architectural education in the design studio, in particular the role of visual representations of a code-based design process in the production of shared knowledge
A day at a time: caregiving on the edge in advanced COPD
The human cost of advanced chronic obstructive pulmonary disease (COPD) for informal caregivers in Canada is mostly unknown. Formal care is episodic, and informal caregivers provide the bulk of care between exacerbations. While patients fear becoming burdensome to family, we lack relevant data against which to assess the validity of this fear. The purpose of our qualitative study was to better understand the extent and nature of ‘burden’ experienced by informal caregivers in advanced COPD. The analysis of 14 informal caregivers interviews yielded the global theme ‘a day at a time,’ reflecting caregivers’ approach to the process of adjusting/coping. Subthemes were: loss of intimate relationship/identity, disease-related demands, and coping-related factors. Caregivers experiencing most distress described greater negative impact on relational dynamics and identity, effects they associated with increasing illness demands especially care recipients’ difficult, emotionally controlling attitudes/behaviors. Our findings reflect substantial caregiver vulnerability in terms of an imbalance between burden and coping capacity. Informal caregivers provide necessary, cost-effective care for those living with COPD and/or other chronic illness. Improved understanding of the physical, emotional, spiritual, and relational factors contributing to their vulnerability can inform new chronic care models better able to support their efforts
In situ measurement of bovine serum albumin interaction with gold nanospheres
Here we present in situ observations of adsorption of bovine serum albumin (BSA) on citratestabilized
gold nanospheres. We implemented scattering correlation spectroscopy as a tool to
quantify changes in the nanoparticle Brownian motion resulting from BSA adsorption onto the
nanoparticle surface. Protein binding was observed as an increase in the nanoparticle
hydrodynamic radius. Our results indicate the formation of a protein monolayer at similar albumin
concentrations as those found in human blood. Additionally, by monitoring the frequency and
intensity of individual scattering events caused by single gold nanoparticles passing the
observation volume, we found that BSA did not induce colloidal aggregation, a relevant result
from the toxicological viewpoint. Moreover, to elucidate the thermodynamics of the gold
nanoparticle-BSA association, we measured an adsorption isotherm which was best described by
an anti-cooperative binding model. The number of binding sites based on this model was
consistent with a BSA monolayer in its native state. In contrast, experiments using poly-ethylene
glycol capped gold nanoparticles revealed no evidence for adsorption of BSA
Application of isothermal titration calorimetry in evaluation of protein–nanoparticle interactions
Nanoparticles (NPs) offer a number of advantages over small organic molecules for controlling protein behaviour inside the cell. Protein binding to the surface of NPs depends on their surface characteristics, composition and method of preparation (Mandal et al. in J Hazard Mater 248–249:238–245, 2013). It is important to understand the binding affinities, stoichiometries and thermodynamical parameters of NP–protein interactions in order to see which interaction will have toxic and hazardous consequences and thus to prevent it. On the other side, because proteins are on the brink of stability, they may experience interactions with some types of NPs that are strong enough to cause denaturation or significantly change their conformations with concomitant loss of their biological function. Structural changes in the protein may cause exposure of new antigenic sites, “cryptic” peptide epitopes, potentially triggering an immune response which can promote autoimmune disease (Treuel et al. in ACS Nano 8(1):503–513, 2014). Mechanistic details of protein structural changes at NP surface have still remained elusive. Understanding the formation and persistence of the protein corona is critical issue; however, there are no many analytical methods which could provide detailed information about the NP–protein interaction characteristics and about protein structural changes caused by interactions with nanoparticles. The article reviews recent studies in NP–protein interactions research and application of isothermal titration calorimetry (ITC) in this research. The study of protein structural changes upon adsorption on nanoparticle surface and application of ITC in these studies is emphasized. The data illustrate that ITC is a versatile tool for evaluation of interactions between NPs and proteins. When coupled with other analytical methods, it is important analytical tool for monitoring conformational changes in proteins
Substitution effects on the photophysical and photoredox properties of tetraaza[7]helicenes
A series of substituted derivatives of tetraaza[7]helicenes were synthesized and the influence of the substitution on their photophysical and photoredox-catalytic properties was studied. The combination of their high fluorescence quantum yields of up to 0.65 and their circularly polarized luminescence (CPL) activity results in CPL brightness values (BCPL) that are among the highest recorded for [7]helicenes so far. A sulfonylation/hetarylation reaction using cyanopyridines as substrates for photoinduced electron transfer (PET) from the excited helicenes was conducted to test for viability in photoredox catalysis. DFT calculations predict the introduction of electron withdrawing substituents to yield more oxidizing catalysts
Observation of Charge-Dependent Azimuthal Correlations in p-Pb Collisions and Its Implication for the Search for the Chiral Magnetic Effect
Peer reviewe
Building, scaling, and sustaining a learning health system for surgical quality improvement: A toolkit
This article describes how to start, replicate, scale, and sustain a learning health system for quality improvement, based on the experience of the Michigan Surgical Quality Collaborative (MSQC). The key components to operationalize a successful collaborative improvement infrastructure and the features of a learning health system are explained. This information is designed to guide others who desire to implement quality improvement interventions across a regional network of hospitals using a collaborative approach. A toolkit is provided (under Supporting Information) with practical information for implementation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156156/3/lrh210215.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156156/2/lrh210215-sup-0001-supinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156156/1/lrh210215_am.pd
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