Impact of Marangoni instabilities on the fluid dynamic behaviour of organic droplets

Marangoni instabilities in dispersed liquid/liquid systems occur if the local solute concentration varies over the interface. The additional shear stress at the interface between a droplet and an ambient phase generates complex convection patterns which increase temporarily the global drag coefficient of the drop and thus retard the drop rise velocity. When Marangoni effects get weaker, the shear forces decrease and the drop reaccelerates. In the present experimental study, the transient drop rise velocity has been intensely investigated in the system toluene_(d)/acetone_(s)/water_(c) for different initial solute concentrations and different drop diameters. Both mass transfer directions have been considered. The reacceleration time as an indicator of the end of Marangoni dominance can be expressed as a function of drop diameter and initial solute concentration.     

Evaluation of a new fibre colonoscope the Olympus TCF-2L

Experience with the new Olympus twin channel TCF-2L colonoscope is presented. Based on 60 examinations including 25 polypectomies it is concluded that the instrument when compared with other colonoscopes is easier to handle and its advancement within the colon is faster, smoother and therefore less disagreeable to the patient. The proximal colon is easier to reach than previously experienced. Polypectomy and retrieving of polyps can efficiently be undertaken. This instrument will undoubtedly further enhance the usefulness and therapeutic value of fibre colonoscopy.     

Tailorable Thermal Properties Through Reactive Blending Using Orthogonal Chemistries and Layer‐by‐Layer Deposition of Poly(1,3,5‐hexahydro‐1,3,5‐triazine) Networks

The ability to tune both the thermal and mechanical properties of poly(1,3,5‐hexahydro‐1,3,5‐triazine)s (PHTs) is critical to meet the increasingly stringent demands of structural materials. To this end, PHTs are modified during the process of vitrification using a reactive blending technique. Two strategies are employed: (i) the incorporation of a monomer or oligomer that contains amino end groups that are integrated into the network via hemiaminal chemistry and (ii) the incorporation of functional monomers bearing reactive end groups capable of self‐polymerization, as well as insertion by copolymerization with the PHT‐forming reagents to form mixed networks. Both strategies produce homogeneous materials, mitigating any adverse thermal properties of the parent PHT material. Here, a deposition method bringing the PHT technology platform to more diverse, economical and large‐scale applications is also introduced. A unique layer‐by‐layer spray‐coating approach of solutions containing 4,4′‐oxydianiline (ODA) and multifunctional amines obtained by conjugate addition to acrylates is developed, allowing for the preparation of large‐scale PHT‐polymer blend films. The ODA–PHT enables high strength and modulus of the final material, while incorporation of acrylates provide an economical approach to polymer blends with tremendous functional group diversity and will allow for recyclability under mild conditions.     

Labour migration and freedom of movement in the European Union: Social exclusion and economic development

There are many reasons why freedom of movement is desirable, but one of the most persuasive arguments in its favour lies in its potential to combat social exclusion by bringing supplies of labour into the places where a demand for labour exists. In fact, there is very little evidence that the dismantling of internal obstacles to migration within the European Union (EU) has created the sort of migration flows which would suggest that free movement is working in this way. It is also apparent that existing migration patterns within the EU are not of the type that would do much to ameliorate patterns of social exclusion, but even if they were there is a risk that—if not properly planned and managed—such movements might exacerbate problems of social exclusion. This paper concludes with a discussion of the confused and ambiguous relationships between migration, exclusion and economic development.     

Biallelic Variants in PYROXD2 Cause a Severe Infantile Metabolic Disorder Affecting Mitochondrial Function

Pyridine Nucleotide-Disulfide Oxidoreductase Domain 2 (PYROXD2; previously called YueF) is a mitochondrial inner membrane/matrix-residing protein and is reported to regulate mitochondrial function. The clinical importance of PYROXD2 has been unclear, and little is known of the protein’s precise biological function. In the present paper, we report biallelic variants in PYROXD2 identified by genome sequencing in a patient with suspected mitochondrial disease. The child presented with acute neurological deterioration, unresponsive episodes, and extreme metabolic acidosis, and received rapid genomic testing. He died shortly after. Magnetic resonance imaging (MRI) brain imaging showed changes resembling Leigh syndrome, one of the more common childhood mitochondrial neurological diseases. Functional studies in patient fibroblasts showed a heightened sensitivity to mitochondrial metabolic stress and increased mitochondrial superoxide levels. Quantitative proteomic analysis demonstrated decreased levels of subunits of the mitochondrial respiratory chain complex I, and both the small and large subunits of the mitochondrial ribosome, suggesting a mitoribosomal defect. Our findings support the critical role of PYROXD2 in human cells, and suggest that the biallelic PYROXD2 variants are associated with mitochondrial dysfunction, and can plausibly explain the child’s clinical presentation.     

A 100 Mb/s multi-LAN crosspoint chip set for cable management

A multi-LAN, 0 dB insertion loss, analog crosspoint switch chip-set is described which forms the heart of a new LAN cable management product. The chip-set is capable of switching FDDI (TP-PMD), ethernet, token ring, and half-duplex protocols through a matrix of 108×108 differential cross-connects, for services using 100 m of unshielded twisted pair cabling and data rates of up to 100 Mb/s, using commercial CMOS and BiCMOS technologies. Using this chip set, it is possible to construct the largest 0 dB insertion-loss programmable analog crosspoint (108×108), operating at 100 Mb/s, currently available