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Functional Part (functional + part)

Distribution by Scientific Domains

Life Sciences	50%
Chemistry	50%

Selected Abstracts

Characterization of microseparator/classifier with a simple arc microchannel

AICHE JOURNAL, Issue 1 2009
Nobuo Oozeki
Abstract Experimentally characterized is a novel microseparator/classifier, whose functional part is an arc microchannel with a width of 200 ,m, depth of 150 ,m, and radius of 20 mm. First, a unique separation principle due to shear-induced lift force is visually demonstrated with neutrally buoyant particles. The device performance is subsequently measured in terms of cut size, separation sharpness, and feed pressure for slightly denser acrylic particles. Compared with representative hydrocyclones, the present device is found to attain significantly smaller cut size at comparable feed pressure, and vice versa. It is finally shown that the device performance remains highest below a critical Stokes number because of no or negligible shear-induced interparticle collisions. It is concluded that the device is to operate with a high efficiency based on the proposed Stokes number. © 2008 American Institute of Chemical Engineers AIChE J, 2009 [source]

Dose-Dependent Immunohistochemical Changes in Rat Cornea and Retina after Oral Methylphenidate Administration

ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2009
E. Tunc
Summary Methylphenidate hydrochloride (MPH), more commonly known as Ritalin, is a piperidine derivative and is the drug most often used to treat attention deficit/hyperactivity disorder, one of the most common behavioural disorders of children and young adults. The aim of this study was to investigate dose-dependent immunohistochemical Dopamine 2 receptor (D2) expression and apoptosis in the rat cornea and cornea. In this study, 27 female pre-pubertal Wistar albino rats, divided into three different dose groups (5, 10 and 20 mg/kg) and their control groups, were used. They were treated orally with methylphenidate dissolved in saline solution for 5 days per week during 3 months. At the end of the third month, after perfusion fixation, eye tissue was removed. Paraffin sections were collected for immunohistochemical and terminal deoxynucleotidyl-transferase-mediated dUTP-biotin nick end labelling assay studies. In our study, we observed that the cornea D2 receptor reactivity showed a dose-related increase after MPH treatment, especially in basal cells of the epithelium and a dose-dependent decrease in the retinal ganglion cell which was statistically meaningful. Analysis of the cornea thickness results showed no meaningful difference between groups. Apoptotic cell number showed a meaningful increase in the high dose treated group compared to the other groups of the study. The data suggest that Ritalin has degenerative effect on the important functional part of the eye, such as cornea and retina and its activating dopaminergic mechanism via similar neuronal paths, functionally and structurally, to induce morphological changes. As a result, we believe that this morphological changes negatively effecting functional organization of the affected cornea and retina. [source]

The subdural space of the spine: A lymphatic sink?

CLINICAL ANATOMY, Issue 7 2010
Myodil's last message
Abstract Following the radiological study of a large number of myelograms, starting over 50 years ago when the only clinical contrast medium available to show the contents of the spinal canal was an iodized oil, the author has collected a number of examples where the oil was inadvertently injected into the subdural area, rather than the intended subarachnoid space. By taking follow-up films at various intervals following the inadvertent injection, it has been possible to study the extent to which the subdural space could become visualized from a lumbar injection, the contrast medium sometimes passing to the top of the cervical region and the lower part of the sacrum. Also, the contrast passed outward along the peri-neural lymphatic sheaths or spaces of the issuing spinal nerves, where it might remain for months, and under the influence of gravity it could extend for a considerable way. It also passed into abdominal and thoracic lymph vessels and nodes. Considering the morphology, predictability, and ease with which the demonstrated subdural space fills, the author concludes that the subdural region is a true and functionally significant "space," and an important conduit or functional part of the body's lymphatic system. He also considers that it has implications for the spread or dissemination of various organisms, substances or pathological conditions, as well as being part of the normal conduit for reabsorption of CSF with implications for hydrocephalus, and with potential for misplacement of spinal anaesthetic agents. Clin. Anat. 23:829,839, 2010. © 2010 Wiley-Liss, Inc. [source]

Interfacing biocatalysis and organic synthesis,

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 12 2007
Roland Wohlgemuth
Abstract The path to new chemical entities often shows the limitations of existing tools both in biocatalysis and organic chemistry. Organic synthetic procedures to prepare a compound in a target-oriented synthesis can damage other functional parts of the molecule. Protection,deprotection schemes can lead to a dead end, when a certain protecting group cannot be cleaved off. In biocatalysis, on the other hand, the required biocatalytic toolbox and methodology might not be readily available, therefore limiting a biocatalytic approach. New toolboxes, ingredients, and methodologies at the interface of classical organic synthesis and biocatalytic reactions bridge the gap between these two areas. Since product isolation and purification involves a substantial amount of time in the preparation of chemicals, methodologies to simplify these tasks are necessary to get the pure product into the bottle with less work-up time. Efficient and safe new pharmaceuticals, intermediates and analytical reagents need to be prepared under certain safety, health, environmental and economical boundary conditions. Biocatalytic reactions have been shown to overcome these limitations successfully and are becoming increasingly important in industrial manufacturing. Building bridges between biocatalysis and organic synthesis will therefore create roads to new synthetic strategies and technological frontiers of both fundamental and practical interest. Copyright © 2007 Society of Chemical Industry [source]