Chiral liquid crystalline side chain polymers

Summary Optically active liquid crystalline side chain polymers with dif ferent flexible spacer groups (n=2–11) and different main chains (acry lates, methacrylates and α chloroacrylates) are described. (+)-2-methyl butyloxyphenyl esters of benzoic acid were chosen as the mesogenic group.     

Western blot monitoring of disseminated Nocardia nova infection treated with clarithromycin, imipenem, and surgical drainage

A case of disseminated infection due to Nocardia nova with subcutaneous popliteal and retrosternal abscesses and lung involvement in an immunocompromised patient is reported. The patient did not respond to sulfonamide therapy. Clinical recovery was obtained upon treatment with imipenem then clarithromycin. Western blot studies revealed an antibody response to a known Nocardia-specific 55-kDa antigen in four successive sera samples collected in the period from the time of admission to seven months later. The resolution of the disseminated nocardiosis and efficacy of the clarithromycin treatment were assessed on the basis of disappearance of the antibodies to the 55-kDa antigen, without invasive sampling.     

Acrodermatitis chronica atrophicans in an 11-year-old girl

We report a case of acrodermatitis chronica atrophicans in an 11-year-old girl living in an area endemic for Lyme borreliosis. The diagnosis was first made on the basis of clinical, histopathological and serological findings. Moreover, Borrelia burgdorferi-specific DNA was amplified from lesional skin by polymerase chain reaction. Intravenous treatment with ceftriaxone (2 g once daily) for 2 weeks was initiated. The skin changes clearly responded to the therapy, and Borrelia burgdorferi-specific gene segments were no longer detectable by polymerase chain reaction. This is the first report of molecular-proven acrodermatitis chronica atrophicans in childhood. The occurrence of this late skin manifestation of Lyme borreliosis in children is reviewed.     

CT of abdominal wall implantation metastases after abdominal percutaneous procedures

PURPOSE: Our goal was to report the CT manifestations of abdominal wall implantation metastases occurring after abdominal percutaneous procedure. METHOD: CT scans and clinical data of six patients with abdominal wall implantation metastases at the puncture site following abdominal percutaneous procedure were reviewed. The abdominal percutaneous procedures included drainage of intraperitoneal abscess in patients with colon or gastric cancer (n = 2), transhepatic biliary drainage in a patient with hilar cholangiocarcinoma (n = 1), biopsy of intrahepatic hepatocellular carcinoma (n = 1), biopsy of a metastatic left adrenal gland (n = 1), and laparoscopic cholecystectomy in a patient with unsuspected gallbladder cancer (n = 1). RESULTS: CT enabled the diagnosis of abdominal wall implantation metastasis in all six patients and showed coexisting intraabdominal tumor sites in five patients. All abdominal wall implantation metastases were homogeneous before intravenous administration of iodinated contrast material and became moderately heterogeneous on contrast-enhanced CT scan with marked enhancement relative to adjacent tissues. CONCLUSION: Abdominal wall implantation metastases are moderately heterogeneous on contrast-enhanced CT scan with marked enhancement relative to adjacent tissues. In most cases of abdominal wall implantation metastasis following abdominal percutaneous procedure, CT shows additional intraabdominal tumor sites. This complication may occur following a variety of abdominal percutaneous procedures (either radiological or surgical).     

Attentional sequence-based recognition: Markovian and evidential reasoning

Biological vision systems explore their environment via allocating their visual resources to only the interesting parts of a scene. This is achieved by a selective attention mechanism that controls eye movements. The data thus generated is a sequence of subimages of different locations and thus a sequence of features extracted from those images - referred to as attentional sequence. In higher level visual processing leading to scene cognition, it is hypothesized that the information contained in attentional sequences are combined and utilized by special mechanisms - although still poorly understood. However, developing models of such mechanisms prove out to be crucial - if we are to understand and mimic this behavior in robotic systems. In this paper, we consider the recognition problem and present two approaches to using attentional sequences for recognition: Markovian and evidential reasoning. Experimental results with our mobile robot APES reveal that simple shapes can be modeled and recognized by these methods - using as few as ten fixations and very simple features. For more complex scenes, longer attentional sequences or more sophisticated features may be required for cognition.     

Bayesian Computations for a Class of Reliability Growth Models

In this article, we consider the development and analysis of both attribute- and variable-data reliability growth models from a Bayesian perspective. We begin with an overview of a Bayesian attribute-data reliability growth model and illustrate how this model can be extended to cover the variable-data growth models as well. Bayesian analysis of these models requires inference over ordered regions, and even though closed-form results for posterior quantities can be obtained in the attribute-data case, variable-data models prove difficult. In general, when the number of test stages gets large, computations become burdensome and, more importantly, the results may become inaccurate due to computational difficulties. We illustrate how the difficulties in the posterior and predictive analyses can be overcome using Markov-chain Monte Carlo methods. We illustrate the implementation of the proposed models by using examples from both attribute and variable reliability growth data.     

(Zr/Ti) ratio effect on RF magnetron sputtered lead titanate zirconate films

Abstract

Sputtered Pb(Zr_xTi_1?x)O₃ thin films with various (Zr/Ti) compositions ranging from 15/85 to 70/30 were grown and characterised in terms of structural and electrical properties. PZT thin films, with 0.7–0.8μm thickness, were deposited on Si/SiO₂/Ti/Pt by sputtering followed by conventional annealing. The sputtering conditions were the same for all the compositions. There were no apparent differences in crystallographic orientation as a function of Zr/Ti and the films a-lattice constant evolution is not exactly identical to the one of bulk ceramics. The permittivity increases when the Zr concentration increases and decreases just after the mor-photropic composition i.e. Zr-rich films. The ferroelectric properties are very sensitive to the Zr/Ti ratio. For example, the coercive field increases when the Ti concentration in the film increases.     

Macrocystic serous cystadenoma of the pancreas: CT and endosonographic features

Defects in stomatin, alpha-adducin, and beta-adducin have been implicated in erythrocyte disorders of cation permeability. We performed linkage analysis of the genetic loci for these proteins in a large kindred with xerocytosis (dehydrated hereditary stomatocytosis). Using polymerase chain reaction-based genotyping techniques, all three loci are excluded as disease gene candidates.