Drying and Deposition of Picolitre Droplets of Colloidal Suspensions in Binary Solvent Mixtures

Picolitre droplets of colloidal suspensions in a mixture of two solvents are emitted by a drop-on-demand ink jet print head onto coated and uncoated glass substrates. The evaporation rate and internal flows inside the drying droplets are investigated and the deposit pattern formed is related to the drying dynamics. High-speed imaging of the droplet profile from the side al- lows the droplet diameter, height, contact angle and volume to be measured during evaporation. The internal flows throughout dry- ing are visualized by following tracer particles within the fluid with an inverted microscope. The resulting deposits at higher solid content are imaged by scanning electron microscopy in or- der to relate the morphology and fine structure to the internal flows within the droplet. The evaporation of binary solvent mixtures can cause a gra- dient in the surface tension at the liquid-air interface, resulting in a Marangoni flow. The ratio of solvent composition and the surface tension of the more volatile solvent relative to the less volatile solvent is varied, to manipulate the direction and mag- nitude of any introduced Marangoni flow. Pure solvent droplets are compared to mixed binary solvent systems, to determine the importance of Marangoni flows on the morphology of the final deposit

Surfactant Adsorption Kinetics by Total Internal Reflection Raman Spectroscopy. 2. CTAB and Triton X-100 Mixtures on Silica

Total internal reflection (TIR) Raman spectroscopy has been used to study the kinetics of adsorption, desorption, and displacement of mixed surfactant systems at the silica–water interface. The limited penetration depth of the evanescent wave provides surface sensitivity while the chemical sensitivity of Raman scattering permits the determination of the time-dependent composition of the adsorbed film. Principal component analysis is used to deconvolute the Raman spectra with a time resolution of 2 s and a precision of 5% of a monolayer. Both equilibrium and kinetic measurements are presented for the cetyltrimethylammonium bromide (CTAB)/Triton X-100 system over a range of concentrations and compositions. For a total concentration of 2 mM, the adsorption isotherm shows strong synergistic behavior with the addition of small amounts of CTAB (2% of the total surfactant) doubling the adsorbed amount of Triton X-100. This synergism has a marked influence on the kinetics: for example, when Triton X-100 replaces CTAB, the Triton X-100 surface excess overshoots its equilibrium value and returns only very slowly to equilibrium. For systems above the cmc, the repartitioning of surfactant between micelles and monomers results in unexpected behavior during exchange or rinsing of mixed surfactant solutions. For example, during rinsing, the more rapid diffusion of CTAB away from the surface leads to a local increase in the monomer concentration of Triton X-100, resulting in a temporary spike in the Triton X-100 surface excess. Displacement kinetics of CTAB by TX-100 and vice versa are generally slower than the adsorption or desorption of the pure surfactants but cover a wide range of kinetic time scales, depending on the details of the compositions and concentrations of the initial and final solutions

Emergent properties in optically bound matter

Sub-micron particles have been observed to spontaneously form regular two-dimensional structures in counterpropagating evanescent laser fields. We show that collective properties of large numbers of optically-trapped particles can be qualitatively different to the properties of small numbers. This is demonstrated both with a computer model and with experimental results. As the number of particles in the structure is increased, optical binding forces can be sufficiently large to overcome the optical landscape imposed by the interference fringes of the laser beams and impose a different, competing structure

Internal Flows and Particle Transport Inside Picoliter Droplets of Binary Solvent Mixtures

The flows in evaporating droplets of binary mixtures are much more complicated than single solvent systems. Solutal Marangoni flows are generated due to differential evaporation of components. High-speed imaging techniques are used to visualize how internal flows transport particles to build up the end deposit. Circulatory flow along streamlines develops inside droplets at the contact line or central region, depending on the direction of the Marangoni flow. Re-circulation of particles can reduce the build up of a ring stain. Additionally, particles migrate across streamlines to collect at the droplet center independent of where the circulating regions occur. Potential mechanisms for particle migration are discussed, including chemophoresis, thermophoresis and shear-induced migration

The effect of glucagon-like peptide-1 receptor agonists liraglutide and semaglutide on cardiovascular and renal outcomes across baseline blood pressure categories: Analysis of the LEADER and SUSTAIN 6 trials

It is unknown if the cardioprotective and renal effects of glucagon-like peptide-1 receptor agonists are consistent across blood pressure (BP) categories in patients with type 2 diabetes and at high risk of cardiovascular events. Using data from the LEADER (9340 patients) and SUSTAIN 6 (3297 patients) trials, we evaluated post hoc the cardiorenal effect of liraglutide and semaglutide on major adverse cardiovascular events (MACE) and nephropathy by baseline BP categories using a Cox proportional hazards model (treatment and subgroup as factors; adjusted for cardiorenal risk factors). Data from the two trials were analysed separately. In the LEADER and SUSTAIN 6 trials, the prevalence of stage 1 hypertension was 30% and 31%, respectively, and of stage 2 hypertension 41% and 43%, respectively. There was no statistical heterogeneity across the BP categories for the effects of liraglutide (P =.06 for MACE; P =.14 for nephropathy) or semaglutide (P =.40 for MACE; P =.27 for nephropathy) versus placebo. This implies that liraglutide and semaglutide may be beneficial for patients with type 2 diabetes, irrespective of their baseline BP

Duration of diabetes and cardiorenal efficacy of liraglutide and semaglutide: A post hoc analysis of the LEADER and SUSTAIN 6 clinical trials

Cardiovascular risk reduction with liraglutide and semaglutide in patients with type 2 diabetes was demonstrated in the LEADER (ClinicalTrials.gov: NCT01179048) and SUSTAIN 6 (ClinicalTrials.gov: NCT01720446) cardiovascular outcome trials. This post hoc analysis assessed the impact of diabetes duration (<5, 5 to <15, 15 to <25 and ≥25 years at baseline) on cardiorenal efficacy of these human glucagon-like peptide-1 analogues using a Cox proportional hazards model. Proportions of patients in the LEADER trial across diabetes duration strata were 15% (<5 years, n = 1377), 50% (5 to <15 years, n = 4692), 27% (15 to <25 years, n = 2504) and 8% (≥25 years, n = 748); corresponding proportions in the SUSTAIN-6 trial were 13% (<5 years, n = 422), 48% (5 to <15 years, n = 1582), 30% (15 to <25 years, n = 977) and 10% (≥25 years, n = 316). Overall, longer diabetes duration was associated with higher age; higher prevalence of females; history of ischaemic stroke, peripheral arterial disease and insulin use; and inferior renal function. There was an increased frequency of major adverse cardiovascular events (MACE), expanded MACE and nephropathy events with increasing diabetes duration. Liraglutide and semaglutide consistently reduced the risk of cardiorenal outcomes across categories of diabetes duration (P-interaction was not significant for all endpoints analysed)

Duration of diabetes and cardiorenal efficacy of liraglutide and semaglutide: A post hoc analysis of the LEADER and SUSTAIN 6 clinical trials

Cardiovascular risk reduction with liraglutide and semaglutide in patients with type 2 diabetes was demonstrated in the LEADER (ClinicalTrials.gov: NCT01179048) and SUSTAIN 6 (ClinicalTrials.gov: NCT01720446) cardiovascular outcome trials. This post hoc analysis assessed the impact of diabetes duration (<5, 5 to <15, 15 to <25 and ≥25 years at baseline) on cardiorenal efficacy of these human glucagon-like peptide-1 analogues using a Cox proportional hazards model. Proportions of patients in the LEADER trial across diabetes duration strata were 15% (<5 years, n = 1377), 50% (5 to <15 years, n = 4692), 27% (15 to <25 years, n = 2504) and 8% (≥25 years, n = 748); corresponding proportions in the SUSTAIN-6 trial were 13% (<5 years, n = 422), 48% (5 to <15 years, n = 1582), 30% (15 to <25 years, n = 977) and 10% (≥25 years, n = 316). Overall, longer diabetes duration was associated with higher age; higher prevalence of females; history of ischaemic stroke, peripheral arterial disease and insulin use; and inferior renal function. There was an increased frequency of major adverse cardiovascular events (MACE), expanded MACE and nephropathy events with increasing diabetes duration. Liraglutide and semaglutide consistently reduced the risk of cardiorenal outcomes across categories of diabetes duration (P-interaction was not significant for all endpoints analysed)

Effects of glucagon-like peptide-1 receptor agonists liraglutide and semaglutide on cardiovascular and renal outcomes across body mass index categories in type 2 diabetes: Results of the LEADER and SUSTAIN 6 trials

35 and ≥35 kg/m2), and CV and kidney outcomes with GLP-1 RA versus placebo were analysed. All baseline BMI data from LEADER (n = 9331) and SUSTAIN 6 (n = 3290) were included (91% and 92% of patients with overweight or obesity, respectively). In SUSTAIN 6, nominally significant heterogeneity of semaglutide efficacy by baseline BMI was observed for CV death/myocardial infarction/stroke (major adverse CV events, primary outcome of both25, ≥25-&ltAssociations between body mass index (BMI) and the cardiovascular (CV) and kidney efficacy of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in patients with type 2 diabetes (T2D) are uncertain; therefore, data analysed separately from the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER) trial and the Trial to Evaluate Cardiovascular and Other Long-term Outcomes with Semaglutide in Subjects with Type 2 Diabetes (SUSTAIN 6) were examined. These international, randomized, placebo-controlled trials investigated liraglutide and semaglutide (both subcutaneous) in patients with T2D and at high risk of CV events. In post hoc analyses, patients were categorized by baseline BMI (<25, ≥25-<30, ≥30-<35 and ≥35 kg/m2), and CV and kidney outcomes with GLP-1 RA versus placebo were analysed. All baseline BMI data from LEADER (n = 9331) and SUSTAIN 6 (n = 3290) were included (91% and 92% of patients with overweight or obesity, respectively). In SUSTAIN 6, nominally significant heterogeneity of semaglutide efficacy by baseline BMI was observed for CV death/myocardial infarction/stroke (major adverse CV events, primary outcome of both; Pinteraction =.02); otherwise, there was no statistical heterogeneity for either GLP-1 RA versus placebo across BMI categories for key CV and kidney outcomes. The lack of statistical heterogeneity from these cardiorenal outcomes implies that liraglutide and semaglutide may be beneficial for many patients and is probable not to depend on their baseline BMI, but further study is needed.therefore, data analysed separately from the Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER) trial and the Trial to Evaluate Cardiovascular and Other Long-term Outcomes with Semaglutide in Subjects with Type 2 Diabetes (SUSTAIN 6) were examined. These international, randomized, placebo-controlled trials investigated liraglutide and semaglutide (both subcutaneous) in patients with T2D and at high risk of CV events. In post hoc analyses, patients were categorized by baseline BMI (&ltAssociations between body mass index (BMI) and the cardiovascular (CV) and kidney efficacy of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in patients with type 2 diabetes (T2D) are uncertainPinteraction =.02)30, ≥30-&ltotherwise, there was no statistical heterogeneity for either GLP-1 RA versus placebo across BMI categories for key CV and kidney outcomes. The lack of statistical heterogeneity from these cardiorenal outcomes implies that liraglutide and semaglutide may be beneficial for many patients and is probable not to depend on their baseline BMI, but further study is needed

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters