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Accurate and reproducible patient positioning is a critical step in radiotherapy for breast cancer. This has seen the use of permanent skin markings becoming standard practice in many centres. Permanent skin markings may have a negative impact on long-term cosmetic outcome, which may in turn, have psychological implications in terms of body image. The aim of this study was to investigate the feasibility of using a semi-permanent tattooing device for the administration of skin marks for breast radiotherapy set-up.
Materials and methods
This was designed as a phase II double-blinded randomised-controlled study comparing our standard permanent tattoos with the Precision Plus Micropigmentation (PPMS) device method. Patients referred for radical breast radiotherapy were eligible for the study. Each study participant had three marks applied using a randomised combination of the standard permanent and PPMS methods and was blinded to the type of each mark. Follow up was at routine appointments until 24 months post radiotherapy. Participants and a blind assessor were invited to score the visibility of each tattoo at each follow-up using a Visual Analogue Scale. Tattoo scores at each time point and change in tattoo scores at 24 months were analysed by a general linear model using the patient as a fixed effect and the type of tattoo (standard or research) as covariate. A simple questionnaire was used to assess radiographer feedback on using the PPMS.
In total, 60 patients were recruited to the study, of which 55 were available for follow-up at 24 months. Semi-permanent tattoos were more visible at 24 months than the permanent tattoos. Semi-permanent tattoos demonstrated a greater degree of fade than the permanent tattoos at 24 months (final time point) post completion of radiotherapy. This was not statistically significant, although it was more apparent for the patient scores (p=0·071) than the blind assessor scores (p=0·27). No semi-permanent tattoos required re-marking before the end of radiotherapy and no adverse skin reactions were observed.
The PPMS presents a safe and feasible alternative to our permanent tattooing method. An extended period of follow-up is required to fully assess the extent of semi-permanent tattoo fade.
We have used 2.0-μsec microwave pulses at a frequency of 2.856 GHz to rapidly heat thin amorphous yttrium-barium-copper-oxide (YBCO) films deposited onto silicon substrates. The samples were irradiated inside a WR-284 waveguide by single-pass TE10 pulses in a traveling wave geometry. X-ray diffractometry studies show that an amorphous-to-crystalline phase transition occurs for incident pulse powers exceeding about 6 MW, in which case the amorphous YBCO layer is converted to Y2BaCuO5. Microscopy of the irradiated film reveals that the phase transition is brought about by melting of the YBCO precursor film and crystallization of the molten layer upon solidification. Time-resolved in situ experiments of the microwave reflectivity (R) and transmissivity (T) show that there is an abrupt change in R for microwave pulse powers exceeding the melt threshold, so that measurements of R and T can be used to monitor the onset of surface melting.
We are studying the boron nitride system by using a pulsed excimer laser to ablate from hexagonal BN (hBN) targets to form cubic BN (cBN) films. We are depositing BN films on heated (600°C) silicon (100) surfaces in a flowing (0- 10 sccm) ambient background gas of either NH3 or N2 of varying partial pressure (0–100 m Torr). Infrared (IR) reflection spectroscopy indicates the films have short-range hexagonal order. Some films grown at low laser energy densities have shown the cubic phase in IR transmission. Auger electron spectroscopy (AES) indicates the films are nitrogen deficient, which is linked to changes in the target stoichiometry with increasing laser fluence. Raman spectroscopy on the films shows only a strong background luminescence suggesting a high concentration of defects associated with the nitrogen vacancies. Atomic force microscopy (AFM) of the films shows a surface morphology that roughens as the growth rate increases. In order to improve the film stoichiometry it was necessary to actively enhance the nitrogen content of the films. It was found that bombarding films during growth with ions from an ion gun filled with NH3 gas increased the N/B ratio but did not enhance the cubic phase. RF biasing the substrate gave films which showed both cubic and hexagonal features in IR reflection. High resolution transmission electron microscopy (TEM) confirms the presence of cBN grains of ∼ 200Å size in films grown with an RF bias.
We are studying the boron nitride system by using a pulsed excimer laser to ablate from hexagonal BN (hBN) targets to form cubic BN (cBN) films. We are depositing BN films on heated (25 - 800°C) Si (100) surfaces and are using a broad-beam ion source operated with Ar and N2 source gasses to produce BN films with a high percentage of sp3-bonded cBN. In order to understand and optimize the growth and nucleation of cBN films, parametric studies of the growth parameters have been performed. The best films to date show >85% sp3-bonded BN as determined from Fourier-transform infrared (FTIR) reflection spectroscopy. High resolution transmission electron microscopy (TEM) and selected area electron diffraction confirm the presence of cBN in these samples. The films are polycrystalline and show grain sizes up to 30- 40 nm. We find from both the FTIR and TEM analyses that the cBN content in these films evolves with growth time. Initially, the films are deposited as hBN and the cBN nucleates on this hBN underlayer. Importantly, the position of the cBN IR phonon also changes with growth time. Initially this mode appears near 1130 cm-1 and the position decreases with growth time to a constant value of 1085 cm-1. Since in bulk cBN this IR mode appears at 1065 cm-1, a large compressive stress induced by the ion bombardment is suggested. In addition, we report on the variation in cBN percentage with temperature.
Electrical characterization (current versus voltage and capacitance versus voltage) of nonstoichiometric amorphous boron phosphide Schottky diodes for neutron detection is presented. These results are incorporated in a Monte Carlo model of detector response to determine material requirements for a boron phosphide neutron counter.
The extracellular matrix (ECM) is an insoluble network of proteins that provides structural support to multicellular tissues and regulates a variety of cell behaviors. Most metazoan cells express transmembrane proteins, known as integrins, which serve as receptors for many ECM protein ligands (1). Integrins connect the extracellular environment to the intracellular cytoskeleton, and also regulate the signal transduction cascades leading to gene regulatory events. Integrin-mediated adhesion and signaling are essential for the proper formation of most tissues, and they play particularly important roles in vascular development and homeostasis (2).
HISTORY OF INTEGRINS
The discovery of integrins centered around efforts to identify a cell surface receptor for the fibrillar ECM protein fibronectin (FN) (3,4). Biochemical purification of the FN receptor revealed a complex of two proteins of differing molecular weights (5). Subsequent cloning and sequencing of cDNAs encoding components of the FN receptor complex identified two transmembrane proteins, named integrins for their postulated role in linking the ECM to the intracellular cytoskeleton. Soon thereafter, several investigators working in areas ranging from human immunology to fly genetics published the cDNA sequences encoding other transmembrane proteins with striking homologies to the FN receptor (3). Thus, it was realized that integrins represented a multigene family with adhesive functions on diverse cell types. We now know that integrins are heterodimeric proteins consisting of two noncovalently associated subunits, termed α and β. Most integrins recognize multiple ECM ligands, and many ECM proteins can bind to more than one integrin receptor. Integrins and their various ECM ligands play essential roles in virtually every aspect of physiological and pathological blood vessel function.
The sedge genus Kyllinga consists of 40 to 45 species distributed in tropical, subtropical, and warm temperate regions around the world (KUkenthal 1936; Tucker 1987). This genus of low rhizomatous perennials or cespitose annuals is classified in the large cosmopolitan family Cyperaceae. Many Kyllinga species are considered weedy (Holm et al. 1979; Tucker 1987), while Kyllinga nervosa Steudel is considered an important forage plant in Africa (McNaughton 1985).
We are studying the boron nitride system by using a pulsed excimer laser to ablate from hexagonal BN (hBN) targets to form cubic BN (cBN) films. We are depositing BN films on heated (400°C) Si (100) surfaces and are using a broad beam ion source operated with Ar and N2 source gasses to produce BN films with a high percentage of sp3-bonded cBN. The best films to date show ∼85% sp3-bonded BN as determined from infrared (IR) reflection spectroscopy. High resolution transmission electron microscopy (TEM) and selected area electron diffraction (SAD) confirm the presence of cBN in these samples. The films are polycrystalline and show grain sizes up to 500 Å.
Live root material of leafy spurge (Euphorbia spp.) was collected from 38 locations across northern United States, southern Canada, and from 1 location in Austria. These materials were established in a nursery at Lincoln, Nebraska along with E. agraria M. Bieb. and E. cyparissias L. # EPHCY. Nineteen vegetative and reproductive characters, taken from various taxonomic keys, were measured on plants established for a period of 3 yr. Data were compared with previous taxonomic keys of Euphorbia species. A key developed by A. Radcliffe-Smith was used to separate the nursery entries. Leaf width measurements were the most useful taxonomic criteria. Five morphologically separable taxa were observed: E. × pseudovirgata (Schur) Soó, E. esula L. # EPHES, E. uralensis Fisch. ex Link., E. agraria M. Bieb., and E. cyparissias L.
Four flower-color phenotypes were observed in a population of musk thistle (Carduus thoermeri Weinm.). This plant has been commonly referred to as C. nutans L. The four phenotypes were: purple corolla and purple pollen, pink corolla and white pollen, white corolla and purple pollen, and white corolla and white pollen. In four generations, 177 self-pollinated individuals of these four phenotypes produced 2123 progeny plants that were classified. Results support the hypothesis that three independent gene pairs were involved in determining the four flower phenotypes. The gene pairs have been designated P/p, W/w, and Pi/pi. It was postulated that all three dominant alleles, P, W, and Pi, must be present to produce both purple corollas and purple pollen. The p allele prevents color development in both corollas and pollen; the w allele eliminates color in corollas but does not affect pollen color; and the pi allele dilutes corolla color from purple to pink and eliminates pollen color. Height measurements of progenies of self-pollinated plants indicated that decreased plant height was associated with inbreeding. On the basis of the evidence presented, the musk thistle plants used in these experiments appear to belong to a single species.
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