2,069 research outputs found
Fibrinogen adsorption and platelet adhesion to silica surfaces with stochastic nanotopography
In this study, the effect of surface nanoscale roughness on fibrinogen adsorption and platelet adhesion was investigated. Nanorough silica surfaces with a low level of surface roughness (10 nm Rrms) were found to support the same level of fibrinogen adsorption as the planar silica surfaces, while nanorough silica surfaces with higher levels of surface roughness (15 nm Rrms) were found to support significantly less fibrinogen adsorption. All surfaces analyzed were found to support the same level of platelet adhesion; however, platelets were rounded in morphology on the nanorough silica surfaces while platelets were spread with a well-developed actin cytoskeleton on the planar silica. Unique quartz crystal microbalance with dissipation monitoring (QCM-D) responses was observed for the interactions between platelets and each of the surfaces. The QCM-D data indicated that platelets were more weakly attached to the nanorough silica surfaces compared with the planar silica. These data support the role of surface nanotopography in directing platelet-surface interactions even when the adsorbed fibrinogen layer is able to support the same level of platelet adhesion
The Evolution of Bat Vestibular Systems in the Face of Potential Antagonistic Selection Pressures for Flight and Echolocation
PMCID: PMC3634842This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Intrauterine environmental and genetic influences on the association between birthweight and cardiovascular risk factors: studies in twins as a means of testing the fetal origins hypothesis
Evidence has accumulated that low birthweight is associated with several risk factors for cardiovascular disease. However, it is not known whether or not these associations are due to a programmed response to intrauterine malnutrition or genetic factors influencing both birthweight and cardiovascular risk factors. Twin studies offer a unique opportunity to distinguish between intrauterine and genetic origins of the association between birthweight and cardiovascular risk. In our twin cohort, low birthweight was associated with insulin resistance, lower HDL and shorter height within both dizygotic and monozygotic twin pairs, suggesting that these associations are, at least in part, independent of genetic factors. In contrast, low birthweight was associated with blood pressure, total and LDL cholesterol, fibrinogen and sympathetic activation within dizygotic twin pairs, but not within monozygotic twin pairs. These differences between dizygotic and monozygotic twins suggest that these associations are, at least in part, due to genetic factors. Therefore, both intrauterine environmental and genetic factors appear to play a role in the association between birthweight and cardiovascular risk factors. In the future, strategies may be developed targeted at improving or preventing impaired intrauterine growth. However, the effects of interventions that comprise changes in environment within the normal range may be limited due to the possible important role of genetic factor
Aurora kinase A drives the evolution of resistance to third-generation EGFR inhibitors in lung cancer.
Although targeted therapies often elicit profound initial patient responses, these effects are transient due to residual disease leading to acquired resistance. How tumors transition between drug responsiveness, tolerance and resistance, especially in the absence of preexisting subclones, remains unclear. In epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cells, we demonstrate that residual disease and acquired resistance in response to EGFR inhibitors requires Aurora kinase A (AURKA) activity. Nongenetic resistance through the activation of AURKA by its coactivator TPX2 emerges in response to chronic EGFR inhibition where it mitigates drug-induced apoptosis. Aurora kinase inhibitors suppress this adaptive survival program, increasing the magnitude and duration of EGFR inhibitor response in preclinical models. Treatment-induced activation of AURKA is associated with resistance to EGFR inhibitors in vitro, in vivo and in most individuals with EGFR-mutant lung adenocarcinoma. These findings delineate a molecular path whereby drug resistance emerges from drug-tolerant cells and unveils a synthetic lethal strategy for enhancing responses to EGFR inhibitors by suppressing AURKA-driven residual disease and acquired resistance
Antenatal breast expression in women with diabetes: outcomes from a retrospective cohort study
Background: Women with diabetes are sometimes advised to express breast milk antenatally to prepare for
breastfeeding and to store colostrum for infant feeding in preventing or treating hypoglycaemia after the birth. The
acceptability, risks and benefits of this practice have not been evaluated. This was aimed to investigate the pattern
of antenatal breast expression uptake and its relationship with birth outcomes in women with diabetes.
Methods: This was part of a two year retrospective cohort study of pregnant women with diabetes (type 1, 2 and
gestational diabetes) who gave birth during 2001–2003 in Derby Hospitals NHS Foundation Trust (n = 94). The
information on the practice of antenatal breastfeeding expression and birth outcomes was collected via
self-administered questionnaires and by examining maternity records.
Results: Thirty-seven percent of women (35/94) recalled that they were advised to express antenatally and 17% did
(16/94). The mean gestational age at birth for women who hand-expressed was lower than that for those who did
not (mean difference (MD) (95% confidence intervals (CI)): -1.2 (−2.4 to 0.04), p = 0.06). A higher proportion of
babies from the antenatal expression group were admitted to special care baby units (SCBU) (MD (95% CI): 21%
(−3.9 to 46.3).
Conclusions: Less than half the women who stated that they were advised to express, did so. There seems to be
an indication that antenatal breast milk expression and lower gestational age at birth are associated. The trend of a higher rate of SCBU admission for babies from the breast milk expression group compared to those who did not
express antenatally is of concern. An appropriately-powered randomised controlled trial is needed to determine the
safety of this practice and its acceptability to women and health professionals before it can be recommended for
implementation in practice.
Keywords: Diabetes, Antenatal, Breast milk expression, Retrospective, Gestational age, Cohort, Gestation</p
Dijet signals of the Little Higgs model with T-parity
The Littest Higgs model with T-parity (LHT), apart from offering a viable
solution to the naturalness problem of the Standard Model, also predicts a set
of new fermions as well as a candidate for dark matter. We explore the
possibility of discovering the heavy T-odd quark Q_H at the LHC in a final
state comprising two hard jets with a large missing transverse momentum. Also
discussed is the role of heavy flavor tagging.Comment: Changes in text. Some references adde
Pothole Reporting System
The purpose of this project is to create a pothole detection device that can be attached to the underside of a commercial vehicle. Potholes cost motorists around 6.4 billion dollars annually, thus demonstrating the need for a system to aid with the detections and reporting of potholes. The four systems we needed to consider for the implementation of this project were the power system, the sensing system, the data processing system, and the reporting and logging system. Power pulled from the vehicle will enable the sensors and data processing module. The data processing module will analyze the readings from the sensors and output pothole data to the logging and reporting system. The logging and reporting system, located on an android mobile device, will store the pothole locations on a cloud server
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02 TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1 μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos2Δϕ modulation for all ΣETPb ranges and particle pT
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector
The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV
- …
