Thumb reconstruction with a free neurovascular wrap-around flap from the big toe: long-term follow-up of thirty cases

From March 1982 to December 1992, 30 cases of thumb reconstruction with a free neurovascular wrap-around flap from the big toe were performed at Korea University Hospital. Twenty-nine of a total of 30 cases were successful and obtained excellent functional and cosmetic results. Postoperative complications included 1 case of graft failure, 6 partial skin necroses, 1 malunion, and 15 cases of resorption of iliac bone graft including 1 case of fatigue fracture of grafted bone. Even for the first metacarpal neck amputations, thumb reconstruction with a free neurovascular wrap-around flap was possible; however, limitation of motion of the reconstructed thumb and resorption of the grafted bone occurred. Thumb reconstruction with a wrap-around free flap from the big toe gives excellent cosmetic and functional results and causes minimal morbidity on the donor site.     

High‐resolution millimeter‐wave radar systems for visualization of unstructured outdoor environments

This paper examines the use of millimeter‐wave radar systems for visualization and navigation in unstructured outdoor environments. Three types of radar systems are described. The first is a long range, 94 GHz, frequency modulated interrupted continuous wave radar which is capable of producing two‐dimensional (2D) reflectivity images to a range of more than 3 km. This is intended for use in long‐range path planning. The second is a class of medium range 77 GHz frequency modulated continuous wave (FMCW) radar with two axis mirror scanners which is capable of producing high resolution threedimensional (3D) imagery out to 500 m at a reasonably slow frame rate. The final class also operates using the FMCW principle, but at 94 GHz, to produce high resolution 2D and 3D images out to about 50 m at a much higher update rate. These shorter range sensors may be used to determine the traversability of the local terrain. The outputs produced by the different classes of radar are examined and the paper considers their advantages when compared to other sensors such as vision and scanning laser. Using radar images, the final section compiles rules for interpreting radar reflectivity images from a path‐planning perspective. © 2006 Wiley Periodicals, Inc.     

Structural and optical properties of chlorinated plasma polymers

Amorphous hydrogenated chlorinated carbon (a-C:H:Cl) films were produced by the plasma polymerization of chloroform–acetylene–argon mixtures in a radiofrequency plasma enhanced chemical vapor deposition system. The main parameter of interest was the proportion of chloroform in the feed, R_C, which was varied from 0 to 80%. Deposition rates of 80 nm min^? 1 were typical for the chlorinated films. Infrared reflection–absorption spectroscopy revealed the presence of C–Cl groups in all the films produced with chloroform in the feed. X-ray photoelectron spectroscopy confirmed this finding, and revealed a saturation of the chlorine content at ~ 47 at.% for R_C ≥ 40%. The refractive index and optical gap, E₀₄, of the films were roughly in the 1.6 to 1.7, and the 2.8 to 3.7 eV range. These values were calculated from transmission ultraviolet–visible-near infrared spectra. Chlorination leads to an increase in the water surface contact angle from ~ 40° to ~ 77°.     

Material Crystallinity as a Determinant of Triplet Dynamics and Oxygen Quenching in Donor Polymers for Organic Photovoltaic Devices

This paper is concerned with the photophysics of triplet excitons in conjugated donor polymers, and their quenching by molecular oxygen. These photophysics are assayed by transient absorption spectroscopy, and correlated with X‐ray diffraction measurements of relative material crystallinity. Eleven different donor polymers are considered, including representatives from several classes of donor polymers recently developed for organic solar cell applications. Triplet lifetimes in an inert (nitrogen) environment range from <100 ns to 5 μs. A remarkably quantitative correlation is observed between these triplet lifetimes and polymer XRD strength, with more crystalline polymers exhibiting shorter triplet lifetimes. Given the broad range of polymers considered, this correlation indicates that material crystallinity is the dominant factor determining triplet lifetime for the polymers studied herein. The rate constant for oxygen quenching of these triplet states, determined from a comparison of transient absorption data under inert and oxygen environments, also show a correlation with material crystallinity. Overall these dependencies result in the yield of oxygen quenching of polymer triplet states increasing strongly as the crystallinity of the polymer is reduced. These photophysical data are compared with photochemical stability of these donor polymers, assayed by photobleaching studies of polymer films under continuous light exposure in an oxygen environment. A partial correlation is observed, with the most stable polymers being the most crystalline, exhibiting negligible oxygen quenching yields. These results are discussed in terms of the likely origins of the correlations between material crystallinity and photophysics, and in terms of their implications for the environmental stability of such donor polymers in optoelectronic devices.     

Genetic requirements and mutational specificity of the Escherichia coli SOS mutator activity

To better understand the mechanisms of SOS mutagenesis in the bacterium Escherichia coli, we have undertaken a genetic analysis of the SOS mutator activity. The SOS mutator activity results from constitutive expression of the SOS system in strains carrying a constitutively activated RecA protein (RecA730). We show that the SOS mutator activity is not enhanced in strains containing deficiencies in the uvrABC nucleotide excision-repair system or the xth and nfo base excision-repair systems. Further, recA730-induced errors are shown to be corrected by the MutHLS-dependent mismatch-repair system as efficiently as the corresponding errors in the rec+ background. These results suggest that the SOS mutator activity does not reflect mutagenesis at so-called cryptic lesions but instead represents an amplification of normally occurring DNA polymerase errors. Analysis of the base-pair-substitution mutations induced by recA730 in a mismatch repair-deficient background shows that both transition and transversion errors are amplified, although the effect is much larger for transversions than for transitions. Analysis of the mutator effect in various dnaE strains, including dnaE antimutators, as well as in proofreading-deficient dnaQ (mutD) strains suggests that in recA730 strains, two types of replication errors occur in parallel: (i) normal replication errors that are subject to both exonucleolytic proofreading and dnaE antimutator effects and (ii) recA730-specific errors that are not susceptible to either proofreading or dnaE antimutator effects. The combined data are consistent with a model suggesting that in recA730 cells error-prone replication complexes are assembled at sites where DNA polymerization is temporarily stalled, most likely when a normal polymerase insertion error has created a poorly extendable terminal mismatch. The modified complex forces extension of the mismatch largely at the exclusion of proofreading and polymerase dissociation pathways. SOS mutagenesis targeted at replication-blocking DNA lesions likely proceeds in the same manner.     

Quantitative cerebral magnetic resonance imaging during ACTH treatment of multiple sclerosis

Serial MR scans were performed with the 2DFT imaging method and the filtered backprojection imaging method on 12 patients with multiple sclerosis in acute phase, 4 in a relapsing/remitting form, and 8 in a progressive form, before, during and after ACTH treatment. Both T1 and T2mono relaxation times, obtained by fitting transverse magnetization decay curves with a monoexponential function within the apparently normal white matter and the areas of increased signal, were measured. With the backprojection method it was possible to fit the transverse magnetization decay curve with a biexponential function and obtain T2long and T2short relaxation times. The T2mono and T1 relaxation times of the apparently normal white matter were significantly different from those obtained for volunteers, but no significant differences were found before, during, or after treatment. The transverse magnetization decay curves of the areas of increased signal were better fitted by a biexponential function. No significant changes in these relaxation times were observed after ACTH treatment. These results argue against an anti-oedematous action of ACTH and may suggest that it has an immunosuppressant effect.     

Three naphthalenes from root bark of Hibiscus syriacus

Three new naphthalenes, designated as syriacusins A-C, were isolated from the root bark of Hibiscus syriacus. These compounds were identified as 2,7-dihydroxy-6-methyl-8-methoxy-1-naphthalenecarbaldehyde, 2-hydroxy-6-hydroxymethyl-7,8-dimethoxy-1-naphthalenecarbaldehyde, 1-carboxy-2,8-dihydroxy-6-methyl-7-methoxynaphthalenecarbolactone (1-->8), respectively, on the basis of various spectral studies. The compounds inhibited lipid peroxidation with IC50s of 0.54, 5.90 and 1.02 micrograms ml-1, respectively. The first compound also showed cytotoxicity against some human cancer cell lines with an ED50 of 1.5-2.4 micrograms ml-1.     

Development of the PSA TU-3 test for valve train scuffing wear

The development of the valve train scuffing wear test by the CEC PL-35 group is described. This test is run on the PSA TU-3 engine, comprises a cold/low speed and a hot/high speed phase and is of 100 h duration. Oil performance is evaluated in terms of camshaft wear and follower contact pad scuffing merit rating. Studies undertaken by the group to identify those factors essential to the control of test development are described. The evolution of the test, with the introduction of a single point fuel-injected engine, is detailed and the consequences of this on severity and repeatability and reproducibility are discussed.