Ulceration of the ileum in Crohn''s disease: correlation with vascular anatomy

Forty-five cases of gastroschisis and 85 of omphalocele were reviewed. The survival of gastroschisis has dramatically improved over the past 20 years, however, that of omphalocele still remained in the lower value, because the size of the defect and the presence of associated anomalies are prognostic factors. The primary fascial closure was first employed for the patients with gastroschisis and a silo chimney was used for limited cases. On the other hand, for the patients with omphalocele, primary closure was possible in 34 cases, silo chimney was used in 17, and 45 cases had nonoperative management with epithelialization. Among them, nonoperative management using painting was the most reliable therapeutic for omphalocele.     

Syntheses of 12-aminododecanoic and 11-aminoundecanoic acids from vernolic acid

12-Aminododecanoic acid and 11-aminoundecanoic acid, monomer precursors for nylon-12 and nylon-11, respectively, have been synthesized from vernolic (cis-12,13-epoxy-cis-9-octadecenoic) acid via a reaction sequence that includes the formation of 12-oxododecanoic acid oxime. Saponification of vernonia oil, followed by a low-temperature recrystallization at −20°C, gave 51% vernolic acid (97% purity, m.p. 23–25°C). Hydrogenation afforded cis-12,13-epoxystearic acid (m.p. 52–54°C, lit. m.p. 52–54°C), which upon oxidation with periodic acid in tertiary butyl alcohol gave 12-oxododecanoic acid with an isolated yield of 71.0%. Reaction of the oxoacid with hydroxylamine hydrochloride gave 12-oxododecanoic acid oxime, which was catalytically reduced to give 12-aminododecanoic acid with a yield greater than 85% and a melting point of 184–186°C (lit. m.p. 185–187°C). 11-Aminoundecanoic acid was prepared from the 12-oxododecanoic acid oxime via a three-step reaction sequence that involved a Beckmann rearrangement, Hofmann degradation, and hydrolysis. Thus, the aldoxime acid was hydrolyzed in the presence of nickel acetate tetrahydrate to give 11-carbamoylundecanoic acid (48% yield, m.p. 129–131°C, lit. m.p. 129–130°C). The amide was then treated with a solution of sodium methoxide and bromine at 70–80°C to give 11-(methoxycarbonylamino)undecanoic acid at 75% yield (m.p. 84–86°C; elemental analysis, calculated for C₁₃H₂₅NO₄: C, 60.19; H, 9.73; N, 5.40; O, 24.68%; found C, 60.02; H, 9.81; N, 5.26; O, 24.91%), which upon alkaline hydrolysis and subsequent neutralization gave 11-aminoundecanoic acid at 34% yield (m.p. 189–192°C, lit. m.p. 190°C). Mass spectrometric and ¹³C nuclear magnetic resonance data of the previously unreported 11-(methoxycarbonylamino)undecanoic acid is provided.     

Electromagnetic scattering calculated from pair distributionfunctions retrieved from planar snow sections

Electromagnetic wave scattering in dense media, such as snow, depends on the three-dimensional (3D) pair distribution function of particle positions. In snow, two-dimensional (2D) stereological data can be obtained by analyzing planar sections. In this paper the authors calculate the volume 3D pair distribution functions from the 2D stereological data by solving Hanisch's integral equation. They first use Monte Carlo simulations for multisize particles to verify the procedure. Next they apply the procedure to available planar snow sections. A log-normal distribution of particle sizes is assumed for the ice grains in snow. To derive multisize pair functions, a least squares fit is used to recover pair functions for particles with sufficient number density and the hole correction approximation is assumed for the larger particles. A family of 3D pair distribution functions are derived. These are then substituted into dense media scattering theory to calculate scattering. It is found that the computed scattering rates are comparable to those calculated under the Percus-Yevick approximation of pair distribution functions of multiple sizes     

Modeling of collision and coalescence of droplets during microgravity processing of Zn-Bi immiscible alloys

A population balance model is presented for the coarsening of the dispersed phase of liquid-liquid two-phase mixtures in microgravity due to gravity sedimentation and Marangoni migration, which lead to the collision and coalescence of droplets. The model is used to predict the evolution of the size distribution of the dispersed phase in a liquid-phase miscibility gap system, Zn-Bi, which has been used in a number of experimental microgravity processing studies in which significant phase segregation has been observed. The analysis shows that increasing the temperature gradient, gravity level, volume fraction of the dispersed phase, initial average drop radius, initial standard deviation of droplet radii, or the temperature coefficient of the interfacial tension leads to an increase in the rate of droplet growth due to collision and coalescence. Comparison of the distribution evolutions for unimodal and bimodal initial distributions shows that the latter yield significantly more rapid droplet growth. Finally, it is shown that droplet growth can be dramatically reduced with antiparallel orientation of the gravity vector and the temperature gradient, provided that the relative magnitude of these two vectors is properly chosen.     

An investigation into the antimicrobial mechanisms of action of two contact lens biocides using electron microscopy.

Polyquaternium-1 (PQ-1) and myristamidopropyl dimethylamine (MAPD) are biocides used commercially in a contact lens disinfecting solutions. Electron microscopy was used to provide further evidence on the mechanism(s) of action of these agents against a wide range of ocular pathogens including bacteria, fungi and protozoa. Both PQ-1 and MAPD caused multiple forms of damage to the organisms tested, evidenced by structural alterations, blebbing, leakage and cell destruction. The extent of damage and the selectivity against specific type of microorganisms was consistent with the antimicrobial activity of these agents. Although electron microscopy is a powerful tool, it has its limitations when used to examine the mode of action of biocides. Indeed, there was no evidence of gross structural alteration to Acanthamoeba castellani or Aspergillus fumigatus following treatment.     

DRIVING CLAY-WORKING MACHINERY1

Illustrating and describing the application of various power transmitting and speed reducing devices with suggestions for further simplifying the methods of applying motors to machines to be driven.     

Spatial Structure of a Single Mn Impurity State on GaAs (110) Surface

Using a low temperature scanning tunneling microscope (STM), we have manipulated individual Mn adatoms at the GaAs (110) surface to apparently bond with two surface As atoms. In this configuration the Mn atoms, which either are at an interstitial site or have substituted for a surface Ga atom, give rise to strong in-gap levels as probed by spatially resolved STM spectroscopy measurements. Mapping the Mn-induced in-gap bound state shows an unusual spatial structure, with highly anisotropic character. The bound state shares some characteristic features with subsurface Mn and Zn dopants.     

Long-term potentiation facilitates behavioral responding to single-pulse stimulation of the perforant path.

Three experiments, with 32 male hooded Sprague-Dawley rats, examined whether long-term potentiation (LTP) could enhance the stimulus properties of electrical brain stimulation. In Exp I, a paradigm was developed in which single-pulse stimulation of the perforant path (PP) could acquire control over operant responses. Evoked potentials were recorded from the dentate gyrus (DG) to measure the postsynaptic consequences of the stimulus and to monitor synaptic efficacy in the PP–DG synapses. Exp II confirmed the relation between the amount of evoked activity and acquisition rate and also showed that transecting the PP impaired performance. In Exp III, high-frequency stimulation of the PP produced LTP and accelerated subsequent acquisition of behavioral responding to PP stimulation. Results document a link between increases in synaptic efficacy and changes in behavior and thereby demonstrate the ability of LTP to serve as at least 1 component of the neural bases of learning and memory. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)