Publications by authors named "Loeffler W"

A new experimental approach is demonstrated to probe the scattering properties of complex media. Using phase-only modulation of the light illuminating a random scattering sample, we induce and record fluctuations in the reflected speckle patterns. Using predictions from diffusion theory, we obtain the scattering and absorption coefficients of the sample from the average change in the speckle amplitude.

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Background: Loop diuretics play a crucial role in symptom management in patients with fluid overload. There is a paucity of data regarding optimal diuretic dose at hospital discharge for acute decompensated heart failure (ADHF) patients requiring loop diuretics.

Objective: To compare all-cause 30-day readmission in ADHF patients on chronic loop diuretics who had an increase in loop diuretic dose at discharge (relative to their preadmission dose) with patients without a change or a decrease in loop diuretic dose at discharge.

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Objective: To implement and assess the effectiveness of a hybrid learning model using advanced screencasting with embedded assessments in pathophysiology and therapeutics modules.

Design: Two pathophysiology and therapeutics course modules on viral hepatitis and the clinical pharmacokinetics of aminoglycosides were chosen for study. The preclass portion of the hybrid model involved student completion of interactive e-lectures that were created with the use of advanced screencasting and included embedded assessments.

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Rationale And Objectives: The study was designed to evaluate a new digitizing device, the iView (Maxxvision, LLC, Gainesville, FL), which aims to replace the magnifying glass in mammography with real-time film digitization, display, and processing.

Materials And Methods: A receiver operating characteristic (ROC) experiment was performed with 5 certified mammographers and 114 mammograms that were read with and without the iView. A satisfaction survey was also conducted on the system's features and usefulness.

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Background: Transformation of the dependent cost variable is often used to solve the problems of heteroscedasticity and skewness in linear ordinary least square regression of health service cost data. However, transformation may cause difficulties in the interpretation of regression coefficients and the retransformation of predicted values.

Aims Of The Study: The study compares the advantages and disadvantages of different methods to estimate regression based cost functions using data on the annual costs of schizophrenia treatment.

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Although there has been a recent increase in interest in picture archiving and communications systems (PACS) topics, little has been published to assist the non-technical person in understanding the complexities of the technologies required for a PACS implementation. This issue of Current Problems in Radiology defines each PACS component and explains why each is important in a system design. PACS installations at the University of Florida are used as examples to tie the concepts together.

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Localized H-1 magnetic resonance (MR) spectroscopy of the human brain in vivo was performed at a field strength of 1.0 T. Investigations with the stimulated echo acquisition mode included studies in the right frontoparietal area, occipital lobe, cerebellum, and pons of healthy volunteers, as well as studies in two patients with astrocytomas.

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Magnetic resonance angiography.

Can Assoc Radiol J

February 1990

Magnetic resonance imaging allows the visualization of vascular structures without the use of contrast agents. With three-dimensional imaging techniques, based on gradient echo sequences, up to 128 slices can be acquired within a maximum acquisition time of 21 minutes at a spatial resolution of approximately 1 mm. This allows the carotid arteries and major intracerebral vascular structures to be displayed.

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Rhizocticin A, the main component of the antifungal, hydrophilic phosphono-oligopeptides of Bacillus subtilis ATCC 6633, was used for sensitivity testing and experiments into the molecular mechanism of the antibiotic action. Budding and filamentous fungi as well as the cultivated nematode Caenorhabditis elegans were found to be sensitive, whereas bacteria and the protozoon Paramecium caudatum were insensitive. Rhizoctonia solani was inhibited in agar dilution tests but not in diffusion tests.

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Fengycin is an antifungal lipopeptide complex produced by Bacillus subtilis strain F-29-3. It inhibits filamentous fungi but is ineffective against yeast and bacteria. The inhibition is antagonized by sterols, phospholipids and oleic acid, whereas two other unsaturated fatty acids increase the antifungal effect.

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In magnetic resonance imaging (MRI) S/N increases with magnetic field strength. The curve, however, flattens out at higher fields, resulting in diminishing gains as the field strength is increased.

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Proton resonance spectra contain two broad classes of hydrogen-containing compounds: those that are fat-like and those that are water-like. Proton chemical shift imaging is a means to produce water or fat proton images. Three methods of proton chemical shift imaging are discussed.

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Using nuclear magnetic resonance tomography it is possible to produce sectional images of the density and relaxation times of the protons within the human body. After a review of the general principles of nuclear magnetic resonance it is explained how this physical effect can be used for generating tomographic images in medical diagnosis. The major components of an imaging system and the physical and technical potentials and limitations of this new method are described.

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Imaging methods based on nuclear magnetic resonance allow the production of sectional images of the human body without ionizing radiation. It is possible to measure the density and relaxation times of the water protons in body fluids or tissue. This allows not only to obtain morphological information but also to get some insight into the spatial distribution of physiological data.

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Ethericin B(Ia) was isolated together with ethericin A1) from fermentations of Aspergillus funiculosus Tü 680. The structure of ethericin B was established as 4-carbethoxy-5,5'-dihydro-xy-3,3'-dimethyl-diphenyl ether by chemical degradation, mass spectrometry, 1H-NMR and comparison with synthetic 4-carbethoxy-5,5'-dimethoxy-3,3'-dimethyl-diphenyl ether.

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The etiologic agents of human mycoses are discussed in taxonomic order. Some fungal genera are used as examples to describe the general genetical behavior of the various groups. Special features of probable genetical and etiological relevance are mentioned.

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An unknown antibiotic, ophiocordin, C21H22N2O8, MW: 430, was isolated from submerged cultures of Cordyceps ophioglossoides, strain TU 276, grown in a glycerol soybean meal medium at 27 degrees C. The antibiotic was extracted from acidified culture fluids with n-butanol and purified by subsequent column chromatography on DEAE-Sephadex and cellulose. Studies including nuclear magnetic resonance and mass spectrometry resulted in proposals of partial structures of the molecule.

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