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Biomedical subjects

E De Smedt

Publications and source records attributed to E De Smedt.

15 recordsLinked to original sources
PubMed2001

Combination of advanced oxidation processes and gas absorption for the treatment of chlorinated solvents in waste gases.

Treatment of chlorinated organic compounds in waste gases is difficult because of several reasons: these compounds are dioxin precursors when incinerated, and also biological treatment is difficult because of a limited number of suitable microbial degradation pathways. On the other hand, since the 1990s, a new generation of chemical oxidation techniques has been introduced in water treatment. Advanced Oxidation Processes (AOPs) are based on a combination of UV/H202, UV/O3 or H2O2/O3. The combinations result in the generation of OH-radicals, which subsequently attack the organic pollutants. In this work, the treatment of a gas stream (240 L/h) loaded with 20-40 ppmv trichloroethylene (TCE) is presented. Therefore, a combination of an absorption process in a bubble column with a liquid H2O2/O3 initiated oxidation, was investigated. Removal efficiencies, depending on the dosed H2O2 and O3, up to 94% were found. The production of chloride ions was investigated: the Cl-atoms from the removed TCE could be found back as chloride ions. Next to the experimental work, attention was paid to the mechanisms taking place in the proposed concept. Here, a simulation model was developed, considering gas/liquid mass transfer of TCE and ozone, axial liquid dispersion, advective gas and liquid transport and about 29 chemica reaction steps. The modelling allowed a better understanding of the technique and gives insight in its possibilities and limitations. Finally, it can be concluded that the proposed technique shows interesting perspectives: it is able to transform chlorine in chlorinated solvents into chloride ions effectively at ambient temperature conditions.

Absorption↗
PubMed1994

Phase I trial of high-dose fosfestrol in hormone-refractory adenocarcinoma of the prostate.

Androgen deprivation displays the mean therapy of advanced stage prostatic cancer. The development of hormone-resistant disease leads to a fatal tumor progression. High-dose fosfestrol (diethylstilbestrol disphosphate) has been suggested to circumvent hormone resistance and to induce a direct cytotoxic effect. Twenty-one patients with hormone-refractory prostate cancer were enrolled in a phase I trial of continuous infusion of high, daily escalating dose of fosfestrol. Fosfestrol was given in a 3.5 hr infusion in 0.9% normal saline at a starting dose of 1.5 g/d. The dose was increased daily in the same patient according to the following schedule: 1.5, 1.8, 2.4, 3.0, 3.6, 3.9, 4.5, 5.1 and 5.7 g/d. The duration of the infusion was prolonged to 7 or 10.5 hr, if a major side effect occurred. There was neither hematological nor cardiovascular toxicity. The main dose-limiting toxicities were nausea/vomiting in 17 patients, edema in 2 patients, and more than 5% weight gain in 3 patients. The planned maximal dose was reached in 10 patients during a 3.5 hr infusion, and in 3 additional patients, after infusion prolongation. Seven patients experienced a subjective improvement: Prostatic acid phosphatase and prostatic specific antigen decreased in 4 out of 11 and in 7 out of 12 patients, respectively. The suggested dose to phase II trial is 4 g/d in 3.5 hr infusion for a duration of up to 10 days.

Acid Phosphatase↗
PubMed1986

Periventricular metastases of a primary intracranial alpha-fetoprotein-producing germ cell tumor.

Periventricular subependymal lesions were found on CT scan in a young man with growth failure, diabetes insipidus, mental deterioration, and hypogonadism with delayed puberty. An initial very good response to radiotherapy was followed a few months later by a relapse, presenting as a very large tumor in the base of the frontal lobes. Serum alpha-fetoprotein at the time of the relapse was very elevated suggesting that the tumor was largely composed of an endodermal sinus tumor component, which was confirmed at autopsy. The purpose of this report is to stress the importance of the use of tumor markers in a particular clinical and neuroradiological setting.

Adolescent↗
PubMed1984

The accessory costotransverse foramen: a radioanatomical study.

One hundred fifty-six anatomical specimens of cervical vertebrae and 55 C1 and 53 C2 vertebrae were examined for the presence of an accessory costotransverse foramen. We also reviewed 60 cervical spine computed tomographic (CT) scans. The variations of the costotransverse and accessory foramen are discussed. The frequency of the latter is 19% in the anatomical specimens and 45% in CT scans. The local anatomy and the excellent visualization on axial transverse CT are stressed.

Cervical Vertebrae↗
PubMed1980

Sublingual sialography.

A case of specific catheterization of the sublingual gland is presented. The possibility of routine examination of this gland is discussed on the basis of a review of the literature.

Catheterization↗
PubMedDate not supplied

High-resolution computerized tomographic scans of the normal and abnormal ear.

Possible applications of high-resolution computerized tomographic scans to otology are discussed. On the basis of examples, the authors illustrate the normal structure of the ear as well as possible pathologic conditions such as congenital abnormalities, cholesteatoma, neoplasms, trauma, and systemic diseases. The advantages of the current generation of computerized tomographic scanners are reviewed, notably contrast potentialities, radiation load, reconstitution of images at a later time, and storage of imaging data. Drawbacks include the high acquisition price of the equipment and the limited mobility of the scanning gantry.

Child↗
PubMedDate not supplied

Visually evoked potentials evoked by moving unidimensional noise stimuli: effects of contrast, spatial frequency, active electrode location, reference electrode location, and stimulus type.

We determined the relative importance of electrode derivation, stimulus type, spatial frequency and contrast in determining the relative size of the late negative and early positive responses of motion elicited VEPs. Seven subjects aged 22-48 years with normal vision were tested binocularly. Motion onset and motion reversal were employed as modes of stimulus presentation. For both, pseudo-random one-dimensional noise patterns whose peak power was at 5.2, 2.6, 1.3, 0.325 and 0.1625 cycles per degree (cpd) were stimuli. Contrasts were 70% and 5%. Active electrodes were placed at Oz, 5 cm to the left of Oz, 5 cm to the right of Oz and a frontal midline position (Fpz) and referenced to linked mastoids. Transient motion reversal elicited a prominent positive response present in all subjects and at low contrasts. Motion onset VEPs have a complex waveform which may be either predominantly positive or negative. The most important variables in determining whether a prominent positivity or negativity is present in the motion onset VEP are the contrast and the spatial frequencies. Data such as these are first efforts in developing recommendations for the motion VEP.

Acoustic Stimulation↗