21 research outputs found
Adjusted hazard ratio (HR) of cardiovascular health factors and risk of all-cause mortality.
No full text<p>Adjusted for age, education, alcohol intake frequency, study survey year, smoking status, physical activity, BMI, total cholesterol level, blood pressure, fasting glucose level, antihypertensive treatment, hypoglycemic therapy, lipid lowering treatment. CI – confidence interval, BMI – body mass index.</p><p>Adjusted hazard ratio (HR) of cardiovascular health factors and risk of all-cause mortality.</p
The Effective Concentration of Unbound Ink Anchors at the Molecular Printboard
No full textSelf-assembled monolayers terminating in β-cyclodextrin cavities can be used to bind ink molecules and so
provide a molecular printboard for nanopatterning applications. Multivalent or multisite binding strengthens
the attachment of large inks and provides more robust patterns. In the present work we use computer simulations
to probe the behavior of functionalized dendrimer inks at the printboard. We performed a series of long 10
ns fully atomistic molecular dynamics (MD) simulations to measure the effective local concentration of unbound
ink anchor groups at the printboard for a variety of binding modes and also for the partial unbinding prerequisite
for ink diffusion on the printboard. These simulations allow us to describe the conformational space occupied
by partially bound inks and estimate the likelihood of an additional binding interaction. Furthermore, by
simulating the shift from a divalent to monovalent binding mode we show that the released anchor quickly
moves to the periphery of the dendrimer binding hemisphere but then reapproaches the printboard and remains
in the vicinity of alternative binding sites. Secondary electrostatic interactions between the protonated dendrimer
core and hydroxyl groups at the entrance to the β-cyclodextrin cavities give “flattened” dendrimer binding
orientations and may aid dendrimer diffusion on the printboard, allowing the dendrimer to “walk” along the
printboard by switching between different partially bound states and minimizing complete unbinding to bulk
solution, crucial for the application of the printboard in, for example, medical diagnostics
Free Energy Balance Predicates Dendrimer Binding Multivalency at Molecular Printboards
No full textSelf-assembled monolayers (SAMs) terminating in β-cyclodextrin (β-CD) cavities can be used to bind ink molecules
and so provide a molecular printboard for nanopatterning applications. Multivalent, or multisite, binding strengthens
the attachment of large inks to the printboard, yielding more robust patterns. We performed fully atomistic molecular
dynamics (MD) simulations in bulk explicit solvent to probe the conformational space available to dendrimer and
dendrite ink molecules, in both free and bound environments. We show that accurate treatment of both pH effects
and binding conformations gives calculated binding modes in line with known binding multivalencies. We identify
and quantify the steric frustration causing small, low-generation dendrimer inks to bind to the printboard using just
a subset of the available anchor groups. Furthermore, we show that the enhanced binding energy of multisite attachment
offsets the steric strain, the feasibility of a given binding mode thus determined by the relative magnitudes of the
unfavorable steric strain and favorable multisite binding free energies. We use our experimentally validated model
of dendrimer binding to predict the binding mode of novel fluorophoric dendrites and find divalent binding, consistent
with confocal microscopy imaging of pattern formation at molecular printboards
MLK Symposium Opening
No full texthttp://deepblue.lib.umich.edu/bitstream/2027.42/89008/1/1991_MLK_Symposium_Opening_1-19-91.pd
A fortran program for reduction of NMR relaxation data
No full textTitle of program: T12FIT
Catalogue Id: ACFT_v1_0
Nature of problem
NMR relaxation data (free induction decay or spin echo amplitude vs. time) is automatically interpreted in terms of one or two relaxation rates.
Versions of this program held in the CPC repository in Mendeley Data
ACFT_v1_0; T12FIT; 10.1016/0010-4655(84)90021-3
This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019
Quantification of Ink Diffusion in Microcontact Printing with Self-Assembled Monolayers
No full textSpreading of ink outside the desired printed area is one of the major limitations of microcontact printing (μ-CP) with alkanethiol self-assembled monolayers (SAMs) on gold. We use molecular dynamics (MD) computer simulations to quantify the temperature and concentration dependence of hexadecanethiol (HDT) ink spreading on HDT SAMs, modeling 18 distinct printing conditions using periodic simulation cells of ∼7 nm edge length and printing conditions ranging from 7 ink molecules per cell at 270 K to 42 ink molecules per cell at 371K. The computed alkanethiol ink diffusion rates on the SAM are of the same order of magnitude as bulk liquid alkanethiol diffusion rates at all but the lowest ink concentrations and highest temperatures, with up to 20−30 times increases in diffusion rates at the lowest concentration−highest temperature conditions. We show that although alkanethiol surfaces are autophobic, autophobicity is not enough to pin the ink solutions on the SAM, and so any overinking of the SAM will lead to spreading of the printed pattern. Comparison of experimental and calculated diffusion data supports an interpretation of pattern broadening as a mixture of spreading on fully and partially formed SAMs, and the calculated spreading rates establish some of the fundamental limitations of μ-CP in terms of stamp contact time and desired pattern width
Using computer games for instruction: The student experience
No full textComputer games are fun, exciting and motivational when used as leisure pursuits. But do they have similar attributes when utilized for educational purposes? This article investigates whether learning by computer game can improve student experiences compared with a more formal lecture approach and whether computer games have potential for improving performance. Instruction was split between lectures and computer games, and student experiences were recorded using an Experience Sampling Method to capture real-time experience and feelings of flow. Results indicated that student experiences in the game mode showed increased alertness, increased feelings of being active, increased feelings of involvement and an increased perception of challenge. Flow characteristics revealed boredom during standard lectures but anxiety and flow during game modes. Finally, some evidence of improved attainment was evident. By using contemporary interactive approaches such as computer games, student learning experiences and attainment may be improved. Some practical issues of implementing games are also discussed
Molecular Dynamics Study of Naturally Occurring Defects in Self-Assembled Monolayer Formation
No full textOne of the major challenges for nanofabrication, in particular microcontact printing (μ-CP), is the control of molecular diffusion, or “ink spreading”, for the creation of nanopatterns with minimized “smudging” at pattern boundaries. In this study, fully atomistic computer simulations were used to measure the impact of naturally occurring domain boundaries on the diffusion of excess alkanethiol ink molecules on printed alkanethiol self-assembled monolayers (SAM). A periodic unit cell containing approximately one million atoms and with a surface area of 56 nm × 55 nm was used to model a hexadecanethiol SAM on Au(111), featuring SAM domain boundaries and a range of concentrations of excess hexadecanethiol ink molecules diffusing on top. This model was simulated for a total of approximately 80 ns of molecular dynamics. The simulations reveal that domain boundaries impede the diffusion of excess ink molecules and can, in some cases, permanently trap excess inks. There is competition between ink spreading and ink trapping, with the ink/SAM interaction strongly dependent on both the ink concentration and the SAM orientation at domain boundaries. SAM defects thus provide potential diffusion barriers for the control of excess ink spreading, and simulations also illustrate atom-scale mechanisms for the repair of damaged areas of the SAM via self-healing. The ability of domain boundaries to trap excess ink molecules is accounted for using an accessible volume argument, and trapping is discussed in relation to experimental efforts to reduce molecular spreading on SAMs for the creation of ultrahigh resolution nanopatterns
What do patients really know? An evaluation of patients’ physical activity guideline knowledge within general practice
No full textBackground: Physical inactivity is well recognised as one of the leading causes of preventable death. However, little is known about the general public’s knowledge surrounding national physical activity guidelines, particularly within general practice (GP). Setting: Two GPs (York and Maidenhead, UK). Question: Are GP patients aware of the national physical guidelines? Also, are health care professionals routinely raising the issue of physical inactivity and would patients welcome support from health care professionals regarding inactivity? Methodology: A questionnaire was distributed in two GPs over a one-week period to evaluate patients knowledge of the national physical activity guidelines. Results: Ninety-four participants completed the questionnaire over one week (60 female; 34 male), with an average age of 54.2 (standard deviation: 19.9 years). 14% (95% Confidence Interval (CI): 8–22%) of the total participants correctly knew the recommended national guidelines for physical activity. 52% (95% CI: 42–63%) recalled being asked by a health care professional about their activity levels. 46% (95% CI: 35–56%) would welcome support from a health care professional around improving their activity levels. Discussion/Conclusion: Only 14% of responders correctly knew the current national minimum activity guidelines. Encouragingly 46% of participants in our study were interested in physical activity advice from a health care professional. Health care professionals need to be aware that many patients do not know the current physical activity guidelines and recognise that primary care may be an underutilised opportunity to educate and promote physical activity
Accommodating Curvature in a Highly Ordered Functionalized Metal Oxide Nanofiber: Synthesis, Characterization, and Multiscale Modeling of Layered Nanosheets
No full textA key element in the rational design of hybrid organic–inorganic
nanostructures is control of surfactant packing and adsorption onto
the inorganic phase in crystal growth and assembly. In layered single
crystal nanofibers and bilayered two-dimensional (2D) nanosheets of
vanadium oxide, we show how the chemisorption of preferred densities
of surfactant molecules can direct the formation of ordered, curved
layers. The atom-scale features of the structures are described using
molecular dynamics simulations that quantify surfactant packing effects
and confirm the preference for a density of 5 dodecanethiol molecules
per 8 vanadium attachment sites in the synthesized structures. This
assembly maintains a remarkably well ordered interlayer spacing, even
when curved. The assemblies of interdigitated organic bilayers on
V2O5 are shown to be sufficiently flexible to
tolerate curvature while maintaining a constant interlayer distance
without rupture, delamination, or cleavage. The accommodation of curvature
and invariant structural integrity points to a beneficial role for
oxide-directed organic film packing effects in layered architectures
such as stacked nanofibers and hybrid 2D nanosheet systems
