Interfacial Nanoprecipitation toward Stable and Responsive Microbubbles and Their Use as a Resuscitative Fluid

A new approach has been developed to prepare stable microbubbles (MBs) by interfacial nanoprecipitation of bioabsorbable polymers at air/liquid interfaces. This facile method offers robust control over the morphology and chemophysical properties of MBs by simple chemical modifications. This approach is amenable to large‐scale manufacturing, and is useful to develop functional MBs for advanced biomedical applications. To demonstrate this, a MB‐based intravenous oxygen carrier was created that undergoes pH‐triggered self‐elimination. Intravenous injection of previous MBs increased the risk of pulmonary vascular obstruction. However, we show, for the first time, that our current design is superior, as they 1) yielded no evidence of acute risks in rodents, and 2) improved the survival in a disease model of asphyxial cardiac arrest (from 0 to 100 %), a condition that affects more than 100 000 in‐hospital patients, and carries a mortality of about 90 %.     

High-performance fiber-optic temperature sensor using low-coherence interferometry

A temperature-sensor system based on low-coherence interferometry with a fiber Mach-Zehnder interferometer as a phase modulator was implemented. A measurement range of 20 to 800 degrees C with a resolution of 0.025 degrees C (corresponding to 0.0004 fringe) was achieved with a 1-mm-long fiber Fabry-Perot interferometer as the sensing element.     

Ferroelectric PZT Thin Films by Sol-Gel Deposition

Sol-gel spin coating has a low thermal budget, is cheap compared to vacuum-based techniques and is now routinely used to produce dense, pore-free ferroelectric films. PbZrx Ti(1 – x)O3 (PZT) is utilized in most applications because it has a large remanent polarization, high piezo- and pyroelectric coefficients and optimized electromechanical coupling factors, depending on precise composition. This paper will review some of the principles and applications of PZT films and highlight using transmission electron microscopy some of the basic problems and solutions involved in producing device-quality material on Si-substrates.     

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Optical second harmonic generation studies of the nature of the GaAs(100) surface in air

We present in this paper a study of the non-linear optical response of the GaAs/air interface as measured by second harmonic generation. By careful choice of incidence and analysis electric vectors for the radiation the second harmonic response as a function of crystallographic orientation has been characterized for a GaAs(100) surface. The exact origin of the response remains unclear but comments on the surface specificity of the technique are made and the observed anisotropy in the data is explained in terms of the step density of the crystal surface.     

Crystal and molecular structures of three trimethylamine-boron halide adducts: (CH3)3NBCl3, (CH3)3NBBr3, and (CH3)3NBI3

X-ray diffraction data from single crystals of the trimethylamine complexes of the three boron halides, BCl₃, BBr₃, and BI₃, lead to aP2₁/m monoclinic cell containing two molecules for each complex. The unit cell dimensions area = 6·68(1),b = 10·247(3),c = 6·502(6) Å, =116·2(1)° (chloro);a = 6·86(1),b = 10·612(4),c = 6·737(6) Å, = 115·8(1)° (bromo);a = 6·92(2),b = 10·86(1),c = 7·147(6) Å, = 93·9(1)° (iodo). The structures were solved by three-dimensional sharpened Patterson functions and show only the chloro and bromo compounds to be isomorphous. Refinement of 662,718 and 954 observed reflexions for the chloro, bromo and iodo complexes, respectively, using anisotropic thermal parameters yielded conventionalR factors of 0·045, 0·087 and 0·054.The molecules are shown to possess a B—N dative bond, a staggered conformation, and effective 3m (C _3v) symmetry. Average C—N bond lengths are 1·52(1) Å for all three complexes. Boronhalogen bond lengths average 1·864(4), 2·04(2) and 2·28(2) Å, while B—N bond distances are 1·609(6), 1·60(2) and 1·58(3) Å, respectively, for the chloro through iodo compounds. Bond angles are approximately tetrahedral with the C—N—C angle decreasing by several degrees in the Cl Br I series.Based in part on a dissertation submitted by Patty H. Clippard to the Rackham School of Graduate Studies of the University of Michigan, January 1969 in partial fulfillment of the requirements of the Ph.D. Degree.     

Orbital-Overlap control in the solid-state reactivity of beta-azido-propiophenones: selective formation of cis-azo-dimers

Solid-state photolysis of 1a,b yields selectively cis-3a,b. X-ray analysis of 1a,b reveals the molecules adopt an extended structure and as such the crystal packing arrangement consists of planar, pi-stacked molecules. The shortest intermolecular distance between adjacent N-atoms is approximately 3.76 A and would lead to formation of trans-3a,b, whereas cis-3a,b is formed by dimerization between N-atoms that are approximately 3.9 A apart. We propose that the molecular orbital alignment of the adjacent nitrenes controls the solid-state reactivity.