Background: Due to their huge biodiversity and the capability to produce a wide range of secondary metabolites, lichens have a great potential in biotechnological applications. They have, however, hardly been used as cell factories to date, as it is considered to be difficult and laborious to cultivate lichen partners in pure or co-culture in the laboratory. The various methods used to isolate lichen fungi, based on either the ascospores, the conidia, or the thallus, have so far not been compared or critically examined.
View Article and Find Full Text PDFTaxonomic identifications in some groups of lichen-forming fungi have been challenge largely due to the scarcity of taxonomically relevant features and limitations of morphological and chemical characters traditionally used to distinguish closely related taxa. Delineating species boundaries in closely related species or species complexes often requires a range of multisource data sets and comprehensive analytical methods. Here we aim to examine species boundaries in a group of saxicolous lichen forming fungi, the Aspiciliella intermutans complex (Megasporaceae), widespread mainly in the Mediterranean.
View Article and Find Full Text PDFThis case report documents the diagnosis, treatment, and outcome of a nonresectable oral squamous cell carcinoma in a dog with initial poor prognosis. An approximately 4-year-old female Staffordshire Bull Terrier presented with a large mass on the front of lower jaw which was diagnosed as oral papillary squamous cell carcinoma by histopathology. CT scans revealed invasion of the cancer to the frenulum of the tongue.
View Article and Find Full Text PDF4-Trifluoromethyl-3-oxo-β-lactams were unexpectedly transformed into 2-[(2,2-difluorovinyl)amino]-2-oxoacetates as major products, accompanied by minor amounts of 2-oxo-2-[(2,2,2-trifluoroethyl)amino]acetates, upon treatment with alkyl halides and triethylamine in DMSO. This peculiar C3-C4 bond fission reactivity was investigated in-depth, from both an experimental and a computational point of view, in order to shed light on the underlying reaction mechanism.
View Article and Find Full Text PDFBackground: Canine diabetes is a strikingly prevalent and growing disease, and yet the standard treatment of a twice-daily insulin injection is both cumbersome to pet owners and only moderately effective. Islet transplantation has been performed with repeated success in canine research models, but has unfortunately not been made available to companion animals. Standard protocols for islet isolation, developed primarily for human islet transplantation, include beating-heart organ donation, vascular perfusion of preservation solutions, specialized equipment.
View Article and Find Full Text PDFBackground: Urban green spaces can harbor a considerable species richness of plants and animals. A few studies on single species groups indicate important habitat functions of cemeteries, but this land use type is clearly understudied compared to parks. Such data are important as they (i) illustrate habitat functions of a specific, but ubiquitous urban land-use type and (ii) may serve as a basis for management approaches.
View Article and Find Full Text PDFAims: Recessive PDX1 (IPF1) mutations are a rare cause of pancreatic agenesis, with three cases reported worldwide. A recent report described two cousins with a homozygous hypomorphic PDX1 mutation causing permanent neonatal diabetes with subclinical exocrine insufficiency. The aim of our study was to investigate the possibility of hypomorphic PDX1 mutations in a large cohort of patients with permanent neonatal diabetes and no reported pancreatic hypoplasia or exocrine insufficiency.
View Article and Find Full Text PDFJuvenile hormone (JH) regulates a wide variety of biological activities in holometabolous insects, ranging from vitellogenesis and caste determination in adults to the timing of metamorphosis in larvae. The mechanism of JH signaling in such a diverse array of processes remains either unknown or contentious. We previously found that the nuclear receptor gene E75A is activated in S2 cells as a primary response to JH.
View Article and Find Full Text PDFThe aim of the present study was to identify food sources of bark-living oribatid mites to investigate if trophic niche differentiation contributes to the diversity of bark living Oribatida. We measured the natural variation in stable isotope ratios ((15)N/(14)N, (13)C/(12)C) in oribatid mites from the bark of oak (Quercus robur), beech (Fagus sylvatica), spruce (Picea abies) and pine (Pinus sylvestris) trees and their potential food sources, i.e.
View Article and Find Full Text PDFThis work evaluates the application of AAPM task group 25 (TG25) methodology for determination of central axis depth dose for a radiotherapy linear accelerator, whose dual scattering foil system and applicators were recently modified. The percent depth dose (%DD) and the dose output factor have been measured for square and rectangular fields at 100- and 110-cm source-to-surface distance (SSDs). At 100-cm SSD, results showed that %DD for a specific energy and field size can vary with applicator, the largest variation being for the 20-MeV, 10 x 10-cm field where a spread of +/- 2.
View Article and Find Full Text PDFA procedure is described to calculate the monitor unit ratios required to produce effective wedge fields having a desired wedge angle by combining an internal 60 degrees wedge with an open field. Complementary procedures are derived and demonstrated for calculating the effective wedge dose distributions with wedge angles of 15 degrees, 30 degrees, and 45 degrees using the central axis depth dose data and off-axis ratios of the open field and the 60 degrees wedged field. Measurements at five points on and off the central axis within each field and measurements of the effective wedge factor demonstrated that the calculated wedge distributions were correctly delivered to within 2% in all cases.
View Article and Find Full Text PDFThe accuracy of dose calculations from a pencil-beam algorithm developed specifically for arc electron beam therapy was evaluated at 10 and 15 MeV. Mid-arc depth-doses were measured for 0 degrees and 90 degrees arcs using 12 and 15 cm radius cylindrical water phantoms. Calculated depth-doses for the 90 degrees arced beams in the build-up region were as much as 3% less than measured values; the maximum dose was similar in magnitude but at a greater depth; and the therapeutic depth, R80, was 2-4 mm deeper.
View Article and Find Full Text PDFIn a beam accessory configuration for a linear accelerator using a prototype multileaf collimator, newly designed wedges were mounted beyond the blocking tray. The isodose curves, depth of maximum dose, surface dose, and wedge transmission factors were measured for the wedges designed for this unique configuration. The same set of wedges was used for both 6- and 18-MV x rays.
View Article and Find Full Text PDFThe feasibility of using film dosimetry data as the input data for patient treatment planning was evaluated. The central-axis depth dose and the off-axis ratios obtained from film measurements in a solid phantom were compared with those of ion-chamber measurements in water. Two techniques were used to generate isodose distributions.
View Article and Find Full Text PDFDosimetry intercomparisons have been performed between the Clatterbridge high-energy neutron facility and the following institutions, all employing beams with similar neutron energies: Université Catholique de Louvain, Belgium; University of Washington, Seattle, USA; MD Anderson Hospital, Houston, USA; and Fermi National Accelerator Laboratory, Batavia, USA. The purpose of the intercomparison was to provide a basis for the exchange of dose-response data and to facilitate the involvement of Clatterbridge in collaborative clinical trials. Tissue-equivalent ionization chambers were used by the participants in each intercomparison to compare measurements of total (neutron plus gamma) absorbed dose in the host institution's neutron beam, following calibration of the chambers in a reference photon beam.
View Article and Find Full Text PDFRadiother Oncol
September 1988
The physical characteristics of the M.D. Anderson Hospital (MDAH) clinical neutron beam are presented.
View Article and Find Full Text PDFThe skin-sparing effects of several filtering materials for fast neutron beams were studied under various conditions. A parallel-plate ionization chamber was used for the measurements. The parameters which were studied included field size, distance from filter to ion chamber, filter material, and filter thickness.
View Article and Find Full Text PDFSeveral target configurations for the 41-MeV (p+,Be) reaction have been evaluated for the characteristics of the radiation field produced; depth dose, dose rate per microA, From analysis, it is concluded that to achieve the desired 13.2-cm depth for 50% of maximum dose and acceptable dose rate at a target-to-skin distance (TSD) of 125-150 cm, the neutron spectra must be filtered to preferentially absorb the lower-energy neutrons. Further increases in depth of 50% of maximum dose and a significant reduction in beryllium heating problems result if a partial transmission target is used with the terminal 30% of proton energy being deposited in a copper target backing.
View Article and Find Full Text PDFThe effects of skin sparing and the gamma/neutron dose ratios in the clinical situations presently in use at the TAMVEC neutron teletherapy facility are not appreciably affected by the presence of filters and/or wedges. It is also shown that if skin sparing is lost due to close proximity of a hydrogenous scattering source, it can be restored by the use of thin lead filters.
View Article and Find Full Text PDFZero-degree neutron energy spectra for the p(41)-Be and d(49)-Be reactions were measured by time-of-flight for neutrons with energies above 1.9 and 1.4 MeV, respectively.
View Article and Find Full Text PDFIn recent years, the use of tissue-equivalent materials has become quite common in fast-neutron dosimetry, with the A-150 plastic developed by Shonka et al. probably the most popular. Information on this specific plastic is scantily reported in the literature and as a consequence a preponderance of authors unknowingly reference an article by Shonka describing an early version of a tissue substitute plastic but having a different elemental composition than the present A-150 formulation.
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