51 research outputs found
Validity of Stokes-Einstein Relation in Soft Colloids up to the Glass Transition
We investigate the dynamics of kinetically frozen block copolymer micelles of
different softness across a wide range of particle concentrations, from the
fluid to the onset of glassy behavior, through a combination of rheology,
dynamic light scattering and pulsed field gradient NMR spectroscopy. We
additionally perform Brownian dynamics simulations based on an ultrasoft
coarse-grained potential, which are found to be in quantitative agreement with
experiments, capturing even the very details of dynamic structure factors S(Q,
t) on approaching the glass transition. We provide evidence that for these
systems the Stokes-Einstein relation holds up to the glass transition; given
that it is violated for dense suspensions of hard colloids, our findings
suggest that its validity is an intriguing signature of ultrasoft interactions.Comment: 5 pages, 4 figures, Supplementary Information, Accepted to Physical
Review Letters (PRL) (2015
Cytochrome P450 2B6 (CYP2B6) and constitutive androstane receptor (CAR) polymorphisms are associated with early discontinuation of efavirenz-containing regimens
Objectives Cytochrome P450 2B6 (CYP2B6) is responsible for the metabolic clearance of efavirenz and single nucleotide polymorphisms (SNPs) in the CYP2B6 gene are associated with efavirenz pharmacokinetics. Since the constitutive androstane receptor (CAR) and the pregnane X receptor (PXR) correlate with CYP2B6 in liver, and a CAR polymorphism (rs2307424) and smoking correlate with efavirenz plasma concentrations, we investigated their association with early (<3 months) discontinuation of efavirenz therapy. Methods Three hundred and seventy-three patients initiating therapy with an efavirenz-based regimen were included (278 white patients and 95 black patients; 293 male). DNA was extracted from whole blood and genotyping for CYP2B6 (516G → T, rs3745274), CAR (540C → T, rs2307424) and PXR (44477T → C, rs1523130; 63396C → T, rs2472677; and 69789A → G, rs763645) was conducted. Binary logistic regression using the backwards method was employed to assess the influence of SNPs and demographics on early discontinuation. Results Of the 373 patients, 131 withdrew from therapy within the first 3 months. Black ethnicity [odds ratio (OR) = 0.27; P = 0.0001], CYP2B6 516TT (OR = 2.81; P = 0.006), CAR rs2307424 CC (OR = 1.92; P = 0.007) and smoking status (OR = 0.45; P = 0.002) were associated with discontinuation within 3 months. Conclusions These data indicate that genetic variability in CYP2B6 and CAR contributes to early treatment discontinuation for efavirenz-based antiretroviral regimens. Further studies are now required to define the clinical utility of these association
Complex dynamics in the vicinity of the sol gel transition: nonergodic and fractal behaviour of poly(acrylamide) gels
Stellbrink J. Complex dynamics in the vicinity of the sol gel transition: nonergodic and fractal behaviour of poly(acrylamide) gels. Aachen: Mainz; 1995
Neutrons for Green Polymers: Structural analysis of polymerisation reactions viareal-time scattering techniques
Flow of concentrated solutions of starlike micelles under large-amplitude oscillatory shear
Neutrons for Green Polymers: Structural analysis of polymerisation reactions viareal-time scattering techniques
Sudden death and ventricular tachycardia in patients with coronary artery disease: Is there a role for coronary revascularization without ICD implantation?
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