Thin-sheet flow between coalescing bubbles

When two spherical bubbles touch, a hole is formed in the fluid sheet between them, and capillary pressure acting on its tightly curved edge drives an outward radial flow which widens the hole joining the bubbles. Recent images of the early stages of this process (Paulsen et al., Nat. Commun., vol. 5, 2014) show that the radius of the hole $r_{\!E}$ at time $t$ grows proportional to $t^{1/2}$, and that the rate is dependent on the fluid viscosity. Here, we explain this behaviour in terms of similarity solutions to a third-order system of radial extensional-flow equations for the thickness and velocity of the sheet of fluid between the bubbles, and determine the growth rate as a function of the Ohnesorge number $\mathit{Oh}$. The initially quadratic sheet profile allows the ratio of viscous and inertial effects to be independent of time. We show that the sheet is slender for $r_{\!E}\ll a$ if $\mathit{Oh}\gg 1$, where $a$ is the bubble radius, but only slender for $r_{\!E}\ll \mathit{Oh}^{2}a$ if $\mathit{Oh}\ll 1$ due to a compressional boundary layer of length $L\propto \mathit{Oh}\,r_{\!E}$, after which there is a change in the structure but not the speed of the retracting sheet. For $\mathit{Oh}\ll 1$, the detailed analysis justifies a simple momentum-balance argument, which gives the analytic prediction $r_{\!E}\sim (32a{\it\gamma}/3{\it\rho})^{1/4}t^{1/2}$, where ${\it\gamma}$ is the surface tension and ${\it\rho}$ is the density.J.P.M. acknowledges an Engineering and Physical Sciences Research Council studentship. C.R.A. and O.A.B. acknowledge the Donors of the American Chemical Society Petroleum Research Fund for partial support of this research. All data accompanying this publication are directly available within the publication.This is the accepted manuscript of a paper published in the Journal of Fluid Mechanics (Munro JP, Anthony CR, Basaran OA, Lister JR, Journal of Fluid Mechanics, 2015, 773, doi:10.1017/jfm.2015.253). The final version is available at http://dx.doi.org/10.1017/jfm.2015.25

Effective mass and band nonparabolicity in remote doped Si/Si0.8Ge0.2 quantum wells

The effective masses in remote doped Si/Si0.8Ge0.2/Si quantum wells having sheet densities, Ns in the range 2 × 1011–1.1 × 1012 cm – 2 have been determined from the temperature dependencies of the Shubnikov–de Haas oscillations. The values obtained increase with magnetic field and Ns. This behavior is taken as evidence for the nonparabolicity of the valence band and accounts for the discrepancies in previously reported masses. Self-consistent band structure calculations for a triangular confinement of the carriers have also been carried out and provide confirmation of the increase in mass with Ns. Theory and experiment give extrapolated Gamma point effective masses of 0.21 and 0.20 of the free-electron mass, respectively

Metal Insulator transition at B=0 in p-SiGe

Observations are reported of a metal-insulator transition in a 2D hole gas in asymmetrically doped strained SiGe quantum wells. The metallic phase, which appears at low temperatures in these high mobility samples, is characterised by a resistivity that decreases exponentially with decreasing temperature. This behaviour, and the duality between resistivity and conductivity on the two sides of the transition, are very similar to that recently reported for high mobility Si-MOSFETs.Comment: 4 pages, REVTEX with 3 ps figure

Compressive Response of Polycrystalline NiCoMnGa High-Temperature Meta-magnetic Shape Memory Alloys

The effects of the addition of quaternary element, Co, to polycrystalline NiMnGa alloys on their magnetic and shape memory properties have been investigated. NiCoMnGa polycrystalline alloys have been found to demonstrate good shape memory and superelasticity behavior under compression at temperatures greater than 100 °C with about 3% transformation strain and low-temperature hysteresis. It is also possible to train the material to demonstrate a large two-way shape memory effect

A somatic origin of homologous Robertsonian translocations and isochromosomes

One t(14q14q), three t(15q15q), two t(21q21q), and two t(22q22q) nonmosaic, apparently balanced, de novo Robertsonian translocation cases were investigated with polymorphic markers to establish the origin of the translocated chromosomes. Four cases had results indicative of an isochromosome: one t(14q14q) case with mild mental retardation and maternal uniparental disomy (UPD) for chromosome 14, one t(15q15q) case with the Prader-Willi syndrome and UPD(15), a phenotypically normal carrier of t(22q22q) with maternal UPD(22), and a phenotypically normal t(21q21q) case of paternal UPD(21). All UPD cases showed complete homozygosity throughout the involved chromosome, which is supportive of a postmeiotic origin. In the remaining four cases, maternal and paternal inheritance of the involved chromosome was found, which unambiguously implies a somatic origin. One t(15q15q) female had a child with a ring chromosome 15, which was also of probable postmeiotic origin as recombination between grandparental haplotypes had occurred prior to ring formation. UPD might be expected to result from de novo Robertsonian translocations of meiotic origin; however, all de novo homologous translocation cases, so far reported, with UPD of chromosomes 14, 15, 21, or 22 have been isochromosomes. These data provide the first direct evidence that nonmosaic Robertsonian translocations, as well as isochromosomes, are commonly the result of a mitotic exchange

The European Registered Toxicologist (ERT) : Current status and prospects for advancement

Acknowledgements We would like to thank the participants of the five workshops in which the issues presented in this paper were discussed and the revised guidelines prepared, as well as the EUROTOX Executive Committee and the societies of toxicology of Sweden, the Netherlands, Switzerland, Austria and France for their support which allowed the workshops to take place.Peer reviewedPostprin

Outcomes in Patients With Metastatic Renal Cell Carcinoma Who Develop Everolimus-Related Hyperglycemia and Hypercholesterolemia: Combined Subgroup Analyses of the RECORD-1 and REACT Trials

In this study we examined the outcome of metastatic renal cell cancer patients with everolimus treatment-related hyperglycemia and hypercholesterolemia. All patients were treated in 2 large, international prospective trials, RECORD-1 (REnal Cell cancer treatment with Oral RAD001 given Daily) and REACT (RAD001 Expanded Access Clinical Trial in RCC). Patients who experienced these events might have experienced an improved response to everolimus. Background Hyperglycemia and hypercholesterolemia are class effects of mammalian target of rapamycin inhibitors. The purpose of this study was to characterize safety and efficacy of patients with metastatic renal cell carcinoma (mRCC) treated with everolimus in RECORD-1 (REnal Cell cancer treatment with Oral RAD001 given Daily) and REACT (RAD001 Expanded Access Clinical Trial in RCC) who developed these events. Patients and Methods Adults with vascular endothelial growth factor–refractory mRCC received everolimus 10 mg/d in the randomized RECORD-1 (n = 277) and open-label REACT (n = 1367) studies. Outcomes included safety, treatment duration, overall response, and progression-free survival for patients who developed hypercholesterolemia or hyperglycemia. Results In RECORD-1, 12% (33 of 277) and 20% (55 of 277) of patients developed any grade hyperglycemia or hypercholesterolemia, respectively, with only 6% (78 of 1367) and 1% (14 of 1367) of the same events, respectively, in REACT. Median everolimus treatment duration was similar for patients with hyperglycemia or hypercholesterolemia (RECORD-1, 6.2 and 6.2 months, respectively; REACT, 4.4 and 4.5 months, respectively), but longer than the overall populations (RECORD-1, 4.6 months; REACT, 3.2 months). In RECORD-1/REACT, 82%/68% of patients with hyperglycemia and 75%/71% of patients with hypercholesterolemia achieved partial response or stable disease. The incidence of clinically notable Grade 3 or 4 adverse events, other than anemia and lymphopenia, appeared to be similar across trials and subgroups. Although there was a trend for improved progression-free survival with development of hyperglycemia or hypercholesterolemia, the association was not statistically significant. Conclusion Hyperglycemia and hypercholesterolemia were observed in low numbers of patients, and although these events might be associated with improved response to everolimus, the differences were not significant. These findings should be validated with prospective biomarker studies

Razine antinuklearnoga antitijela i reumatoidnoga faktora u radnika izloženih silicijevu dioksidu

A lot of workers in industries such as foundry, stonecutting, and sandblasting are exposed to higher than permissible levels of crystalline silica. Various alterations in humoral immune function have been reported in silicosis patients and workers exposed to silica dust. The aim of this study was to measure antinuclear antibody (ANA) and rheumatoid factor (RF) levels in foundry workers exposed to silica and to compare them with a control group without such exposure. ANA and RF were measured in 78 exposed and 73 non-exposed workers, and standard statistical methods were used to compare them. The two groups did not significantly differ in age and smoking. Mean work duration of the exposed and non-exposed workers was (14.9±4.72) years and (12.41±6.3) years, respectively. Ten exposed workers had silicosis. ANA was negative in all workers in either group. Its mean titer did not differ significantly between the exposed and control workers [(0.39±0.15) IU mL-1 vs. (0.36±0.17) IU mL-1, respectively]. RF was positive in two workers of each group. Other studies have reported an increase in ANA and RF associated with exposure to silica dust and silicosis. In contrast, our study suggests that exposure to silica dust does not increase the level of ANA and RF in exposed workers.Mnogi su radnici izloženi kristalnomu silicijevu dioksidu u razinama iznad dopuštenih. U oboljelih od silikoze i radnika izloženih prašinama koje sadržavaju silicijev dioksid zamijećen je niz oštećenja humoralne obrane. Budući da su radnici u ljevaonicama izloženi visokim razinama kristalnoga silicijeva dioksida, u njih bismo očekivali ovakve humoralne poremećaje. Cilj je ovog ispitivanja bio izmjeriti i usporediti razine antinuklearnih protutijela (ANA) i reumatoidnoga faktora (RF) u krvi radnika u ljevaonici izloženih silicijevu dioksidu i neizložene kontrolne skupine. ANA i RF izmjereni su u 78 izloženih radnika i 73 neizložena radnika te su uspoređeni s pomoću standardnih statističkih metoda. Dvije se skupine nisu bitno razlikovale u broju pušača i u dobi. Prosječna duljina radnog vijeka izloženih radnika bila je (14,9±4,72) godine, a neizloženih (12,41±6,3) godine. Deset izloženih radnika imalo je silikozu. Nalazi ANA bili su negativni u obje skupine radnika. Srednja vrijednost titra ANA iznosila je (0,39±0,15) IU mL-1 u izloženih ispitanika, a (0,36±0,17) IU mL-1 u kontrola, što je statistički zanemariva razlika. Nalaz RF-a bio je pozitivan u dva izložena te dva kontrolna radnika. Naše ispitivanje upućuje na to da prašine silicijeva dioksida ne uzrokuju porast razina ANA i RF-a u izloženih radnika

The Raine study had no evidence of significant perinatal selection bias after two decades of follow up: A longitudinal pregnancy cohort study

Background: Cohort studies may increase or decrease their selection bias as they progress through time. The Western Australian Pregnancy Cohort (Raine) Study has followed 2868 children for over two decades; from fetal into adult life. This paper analyses the cohort over time, assessing potential bias that may come and go with recruitment, retention and loss of participants. Methods: Linked data from all births in Western Australian over the 3 years the Raine Cohort was recruited were obtained to compare perinatal characteristics and subsequent health outcomes between the Western Australian (WA) contemporaneous birth population and the Raine Cohort at five time points. Perinatal exposure-outcome comparisons were employed to assess bias due to non-participation in Raine Study subsets. Results: There were demographic differences between the Raine Study cohort and its source population at recruitment with further changes across the period of follow up. Despite these differences, the pregnancy and infant data of those with continuing participation were not significantly different to the WA contemporaneous birth population. None of the exposure-outcome associations were significantly different to those in the WA general population at recruitment or at any cohort reviews suggesting no substantial recruitment or attrition bias. Conclusions: The Raine Study is valuable for association studies, even after 20 years of cohort reviews with increasing non-participation of cohort members. Non-participation has resulted in greater attrition of socially disadvantaged participants, however, exposure-outcome association analyses suggest that there is no apparent resulting selection bias